Monday 22 January 2024

Testing, Testing.

Recently I wrote about some watercolours I've made. Since then I've found some scientific literature on the subject, after discovering that the 'coffee ring effect' is the scientific name of a ring shaped deposit found after a drop of liquid has dried. It's a relatively new field of study, with major research only being done since the late 1990's. This literature does confirm my basic assumption of the movement of the paint particles, which is explained by capillary flow. The literature also shows that there are many competing phenomena and variables at play, which are difficult to measure and analyse. Many of the papers I found focus on variables like temperature, relative humidity and electromagnetic influences, most of which effect the rate of evaporation.

I've done some experiments to test the influence of some of these parameters on the appearance of my own drops of watercolour, with some notable results.

First I tried to measure the influence of temperature. The results of this were mostly inconclusive. To test the influence of temperature, I uniformly applied the droplets at three different temperatures, to see if their appearance would differ after drying. The expected result from some of the literature would be that a higher temperature creates a more even distribution throughout the drying droplet. Various mechanisms have been suggested on how this works, including a greater evaporation at the contact surface with the air, which causes greater flow inside the droplet, as well as a 'surface capture' effect of particles at the contact surface.
In the rudimentary testing I have done I however didn't notice any significant effects of temperature on how uniformly the paint spread through the drying droplet:

Three drops dried at different temperatures

In this image there are three droplets of about 2 mm in diameter, made with Winsor and Newton's Payne's grey watercolour paint. The first was made on a substrate that's cooled below 0ºC, the middle was made at room temperature and the last one was heated after application in an oven to about 70ºC. It's clear that there is little significant variation between these three droplets, thereby giving indication that temperature, at least on this scale and with these materials, is not a significant contributing factor for the distribution of the pigments in the drying droplet.
However, the influence of temperature might be dependent on the exact chemical composition of the pigments, in combination with corresponding changes in the binders used. The following image consists of the results of the same experiment, showing Daniel Smith's Hematite Genuine watercolour paint, in duplicate, at <0ºC, room temperature and ~70ºC, respectively.

Two sets of three drops dried at different temperatures

What one can observe here is greater ring formation with a cooled substrate and more concentration at the center at elevated temperatures. So much so that the ring where the pigment is deposited is not even found at the outer edge of the droplet, which is something I have not observed in other situations. This behaviour is also the exact opposite of what the literature would have us expect.

When examining the literature, it must also be noted that most of the literature on the coffee ring effect seeks to eliminate it, because in an analytical or manufacturing context its existence is commonly detrimental to achieving uniform depositions or measurements. Relatively little literature thus exists on controlling the formation of the ring itself, and as far as I can tell, all research is done on colloids that are mixed prior to droplet formation. Little to no research has been done on the effects of introducing a colloid to an existing droplet. Yet I've found indications that for our purposes this provides a lot of control on the exact formation of the coffee ring, as can be seen in the following image:

Four different ways of introducing the paint

From left to right, this is a simple droplet of a diluted suspension of Winsor and Newton Payne's grey watercolour, a water droplet to which a diluted suspension was added at the centre point of the droplet after droplet formation, a water droplet to which a diluted suspension was added at the right edge of the droplet after droplet formation and a water droplet to which a near-saturated suspension was added at the right edge of the droplet after droplet formation.
As you can see, the two leftmost droplets dried nearly identical, even if their method of application was very different. For the third droplet from the left, paint was added later at an angle on the right edge with the paper, and this saw most of the pigment end up around the full perimeter of the droplet. This process was repeated with a higher concentration of pigment in the last droplet and while this contained far more pigment than the other three droplets, still most of it stayed at the perimeter of the droplet, with even more seemingly remaining at the initial point of introduction.

My explanation for this is that a similar outward pushing effect is at work here, inhibiting the possibility for pigments to enter the centre of the droplet through gravity or other forces.
It must however be also noted that in some degree this is dependent on the exact shape of the droplet and again the composition of the paint.

Three different ways of introducing the paint

In this image we have a droplet with a homogenous solution of Daniel Smith's Venetian Red water colour paint, followed by a saturated solution of the same paint added at the right edge of a droplet of water and ultimately a heavily diluted solution added at the right edge of a droplet of water. They each have their distinctive appearances, which differ subtly from the previous experiment with Payne's grey, most notably with the later introduction of a saturated solution. This produced a light centre with a thick edge in the previous experiment, while it created a mostly even spread with a thin edge in the latter example.

Even though it's difficult to observe this behaviour in real time and at actual scale, I believe the observations from the previous two figures is related to the behaviour of the pigment at the droplet's contact surface with air. I did a test where I placed a small saturated spot of Payne's grey watercolour on a piece of paper, let it dry, and then added a water droplet, without physically disturbing the spot of paint. What I found after this droplet had dried is that the paint had spread uniformly throughout the droplet, with a clear coffee ring effect present. There thus is a tendency for the paint to be distributed inside the droplet if it gets far enough inside. 

Adding water to a dried spot of paint

Generally speaking, predicting the exact behaviour of the interaction of a fluid and a colloid is complex and very difficult, as can be seen in the following example:

Introducing two paints into a single droplet

In this image two different watercolour paints are added to a single droplet. The droplet at the top was a diluted solution of Daniel Smith's Quinacridone Gold water colour paint, to which a saturated solution of Daniel Smith's Quinacridone Red was added on the right side at an angle. The droplet at the bottom was pure water, to which Quinacridone Gold was first added at the top and then Quinacridone Red was added on the right side at an angle. As is clearly visible, the latter process resulted in a nearly homogenous mixture, while the first gave a degree of separation between in the colours in the dried droplet.
However, I then repeated this experiment using Daniel Smith's Quinacridone Gold and Winsor & Newton's Payne's grey.

Introducing two paints into a single droplet

Here the same procedure was followed, with the Payne's Gray being added first, followed by Quincridone Gold on the right side at an angle. The way the paints mixed was the opposite of what I observed in the previous experiment. On this occasion the Quinacridone Gold mixed better with the droplet of diluted water colour, while the two paints stayed separated when added in sequence to a droplet of pure water. At the present time I have no simple explanation for this seeming contradiction in behaviour.

Lastly I want to note another characteristic I hadn't considered up until this point, which is the influence of magnetic effects on the droplets. Naturally electromagnetic effects are strong if there are ferromagnetic pigments present in the paint. Especially in the case of paints that contain a mixture of magnetic and non-magnetic pigments, introducing a magnetic field during the drying process produces interesting effects that can be easily controlled with the presence of any magnetic field. 

In conclusion, about a month has past since the previous post and I have still made some new observations about the behaviour of the watercolour paint inside a droplet. Some of these observations seemingly contradict the explanations found in current scientific literature, while others provide a possibility for new methods that are hitherto unexplored.

Tuesday 16 January 2024

The Artist's Artist's Critic's Critic

During 2023 I recorded most of my visits to exhibitions on a website called The Artist's Artist's Critic's Critic. On this website I scored each exhibition one to five stars on six characteristics: difficulty, entertainment, originality, legibility, consistency and craftsmanship. I also recorded the time spent at the exhibition as an indication of my affinity with the work.
Part of the reason I started this undertaking was to see if I could develop an alternative to the subjective and nonsensical star rating system that's used by various media outlets. By trying to formulate those aspects of an exhibition I adhere importance to, I thought it might be possible to provide some insight into my own viewing behaviour, while still having a numerical ranking system.

Now the year is over I have crunched some of the numbers and it gave some interesting results.

In 2023 I recorded 79 exhibitions. 65 of those were solo shows, of which 31 were at museums, 21 at galleries and 13 at other institutions. Of the 14 group exhibitions I recorded, 7 were at museums and 7 took place at other institutions. I visited no group shows at commercial galleries.

When rating something 1 to 5 stars on six different characteristics, the range of the total scores lies between 6 and 30, with an average of 18. This equates to a 3-star score on all six characteristics.
The average total score I've given to those 79 exhibitions is 18,25, with a median of 18 and modes of 12 and 22. This was surprising to me, to find that I ended up with the factual average as my personal average. That does mean there was some degree of consistency to my judgements, which could be interpreted as a degree of objectivity.

In terms of average score per characteristic, difficulty had the lowest with 2,6; then entertainment with 2,7; originality with 2,9; craftsmanship with 3,3; consistency with 3,4; and legibility with 3,5. Although all scores only deviate from the theoretical average of 3 with maximum 0,5 points, it was surprising to find that legibility scored slightly higher overall. Part of the reason I included legibility as a characteristic was to measure the degree in which the exhibition requires explanation beyond the works themselves. It's good to see I rated only 15 of 79 exhibitions with one or two stars on this point, as I definitely think this is a problem within art in general. But I guess by measuring I found that it's not as big a problem as I thought it was.
That difficulty is the lowest scoring metric doesn't surprise me however. I defined difficulty as the ability of the exhibition to make think and challenge me intellectually, and while I enjoy many exhibitions, these days its rare that they show me something I can't make sense of. In fact, only one exhibition scored five stars on this subject, which was Philip Metten's solo exhibition at Zeno-X gallery in Antwerp.

Broadly speaking, I rated solo shows at galleries the highest, with an average score of 20. Solo shows at institutions received an average score of 19 and solo shows at museums received the true average of 18. Group shows at institutions scored a slightly below average score of 17, but group exhibitions at museums on average scored a mere 14. This is also the biggest deviation from the norm with 4 points. These low scores for group exhibitions reflect my overall impression that curators aren't very good at making exhibitions and that this is especially true for curators working at museums. In fact, the only group show that scored above average was The insincere charm of things at the Balcony in the Hague.

Some interesting low scores came from shows by Anne Imhof, Jenny Holzer, Simon Denny, Kasper Bosmans, Helen Frankenthaler, Ragnar Kjartansson, and Elmgreen & Dragset. These are all normally considered highly rated artists, if not globally then at least in their respective countries of origin. Yet the shows I saw of them in 2023 apparently weren't exactly up to snuff.
I personally found it interesting that Daan van Golden at Micheline Swaczjer had a below average score as well. That just wasn't a very interesting show with works from an artist I otherwise greatly appreciate.

Of course I also have a top five of shows that I've recorded in the past year.
My top show, with a score of 28, was Tomma Abts at galerie Buchholz in Cologne, followed by Thomas Schütte at De Pont in Tilburg. The latter got there purely on the quality of the works themselves, as the curatorial effort was average at best. Third was Jeff Weber's Image Storage Containers at the CNA in Dudelange. I doubt many people have seen that exhibition, but it was very well put together on all fronts and punching well above its weight.
Fourth and fifth place are actually by the same artist, namely Aglaia Konrad at the FOMU in Antwerp and then later in the year also at Mu.Zee in Ostend. Once again just excellently put together shows that merely faltered a little bit on the entertainment factor.

Only one show actually got the average score of all 3-stars and this was Blank. Raw. Illegible..., curated by Moritz Kung at the Leopold Hoesch Museum. It was a comprehensive group show of 'empty' books and about as average as an exhibition can be. The presentation was adequate enough to be unnoticeable, simply unremarkable in every way possible. For an audience it's often hard to understand books when displayed in glass vitrines, but each book was carefully considered and shown in such a way to be as accessible as it could possibly be. The books on display presented a very broad, thoroughly researched overview and thus for every uninteresting work in the exhibition there was also a gem that got you excited. And as unusual the premise of the exhibition was, it was simultaneously also somewhat obvious. If you want to have a yardstick for what a neutral and average exhibition looks like, that is it. It was spectacular how unspectacular it was.

As a final remark I only found a very weak correlation of 0,28 between time spent in the exhibition and the overall score. The bulk of this number comes from the correlation between the scores for entertainment and for difficulty, with a correlation to time spent of respectively 0,40 and 0,32. All other metrics had a correlation of 0,18 or less. So if you make me laugh or think, I'm going to spend (slightly) more time at your exhibition. 

Keeping track of the exhibitions I've visited like this has been an interesting experiment. I would also say that I've mostly succeeded in my attempt to rate the exhibitions as objectively as possible on each of the six characteristics. When all the scores are added up, each exhibition is found in the quartile that corresponds to my more intuitive and 'unfiltered' opinion of that exhibition. I'm not sure if I will continue to keep track of the exhibitions I will visit in the future, but it's been personally interesting to systematically record one's thoughts and I believe it has given some indication that a more objective rating system for exhibitions is possible by using different metrics than those that are commonly used.

Monday 1 January 2024

A Well-Constructed, Meaningful Table is Worth the Extra Money

As an adolescent I never liked chemistry because it didn't make any sense to me. Our high school teacher had us copy equations with strange symbols that seemed to strictly adhere to inexplicable and invisible rules whose full scope and mechanisms couldn't be shown to us students. This is also an experience that seems to be a relatively common one for the people that I've spoken to about the subject.
Now that I've actually learned some of those invisible rules and understand a reasonable amount about how chemistry works, I've come to the conclusion that a substantial part of the perceived difficulty of the natural sciences is partially a problem of graphic design.

And I'm not talking about the kind of 'scientific illustration' design, I'm talking bare bones letterspacing, kerning, tabulation, ink coverage and em spaces.
At its core graphic design is about the structuring of information. While many chemists I know are concerned with how to structure information, very few approach this problem in the same way a graphic designer does. Yet the graphic designer, on their part, rarely understands the context and content of the scientific texts presented to them. Without such understanding it is impossible to accurately structure that information for easier comprehension.

The problem of creating legible texts has naturally existed from the beginning of scientific publishing, especially to those who wish to standardise certain aspects.
The American Chemical Society, or ACS, thus first published its 'Handbook for Authors of Papers in the Research Journals of the American Chemical Society' in 1965. Most of this book is of course about naming conventions, how to write correct molecular structures, and so on. A small part is however concerned with what one would call 'design', even if it is in the abstract sense of the word. For example, the three page long section on tables contains phrases like: 'Tables should be self-explanatory and should supplement, not duplicate, the text and figures'; 'When numerical data are presented in columns, the decimal points must be aligned', and 'ruled lines and brackets may be used in moderation, particularly after column heads and stubs, but they should never be included as a substitute for good alignment, adequate spacing, or clarity.'

Such phrases echo those found in other more graphic design oriented reference works, such as 'The Elements of Typographic Style' by Robert Bringhurst, who has phrased the latter sentiment in the following manner in its section on tables: 'There should be a minimum amount of furniture (rules, boxes, dots and other guide rails for travelling through typographic space) and a maximum amount of information.'
This is perhaps a little more poetic than the previous expression, but both sentences nevertheless stress the fact that the form of the table should befit its content and that the legibility of that content should be the main priority.

Even if the ACS already considered the appearance of such 'table furniture' in 1965, this interest in graphical details quickly seemed to wane and a stronger focus on technical matters took hold.
A new edition of the Handbook was printed in 1978, now titled the 'Handbook for Authors of Papers in American Chemical Society Publications'. This revised edition no longer makes any mention of the appearance of the tables themselves, but further elaborates on the correct formatting of many technical aspects. It suggests, for example, to express multiple measurements in a table as a mean, rather than separate entries. At the instances when this revision does present new guidelines on the visual structure of texts, they are often of questionable merit, such as the suggestion that one should 'keep column widths of comparable size, whenever possible', which can hardly be considered a universal truth.

By 1986 the Handbook was superseded by 'The ACS Style Guide: A Manual for Authors and Editors'. This publication sees the problem of graphic design in terms of practical concerns such as the available space and technical reproducibility, not as an inherent factor contributing to the legibility of the presented information.
The section 'How To Construct Tables' starts with the inspiring reminder that 'tables are much more expensive to typeset than text; the larger the table, the more expensive. A well-constructed, meaningful table is worth the extra money, but anything else is a waste of money and does not enhance your paper.' Further considerations are insights such as: 'if you have three columns that do not relate to each other, perhaps the material is really a list of items and not a table at all' and 'if your table has alignment and positioning requirements, perhaps it should really be a figure'. Which are of course exactly the kind of universally applicable guidelines any chemist is looking for when attempting to construct a legible and concise table. 

The ACS Style Guide was last published in 2006 and kept the same technical focus throughout its lifetime. A general belief in technology solving the problems of design seems to be prevalent in the attitude of its authors. The section on tables in the 2006 edition remained largely unchanged, although it now had some tips on using word-processing software: 'In Microsoft Word or WordPerfect, use the software’s table feature, rather than aligning columns using the tab key. Entries arranged with the table feature are more likely to be properly aligned in publication than entries that have been tabbed.'
That this was very likely a useful tip to a number of their contributors gives some indication of how inexperienced your average scientist may be with genuine problems and solutions of design.

In 2020 the American Chemical Society replaced its style guide with 'The ACS Guide to Scholarly Information'. This is a completely rewritten digital-only guide, which in their own words is the 'go-to tool to help students, librarians, researchers, and educators communicate effectively'.
Unfortunately I couldn't tell you whether or not this 'go-to tool' has any clearer information on the uses of graphic design in scientific texts, as it is shielded by a prohibitively expensive subscription model which is separated from their other publications. While I have easy access to a number of the earlier editions through used bookshops and various libraries, no public or universitary library in Europe presently provides access to 'The ACS Guide to Scholarly Information', even if a large number of them actively subscribe to the journals of the ACS.
Ironically, the only two chapters the ACS provides free access to on their own website are the brand-new chapters on open access and inclusivity, which includes a subchapter on 'socioeconomic status'.

Thus while the importance of legible information is commonly acknowledged in various scientific fields, the large and constantly changing requirements from within those fields have kept scientists unable to focus on increasing the legibility of their work through graphic design.
In turn, the resulting body of poorly structured information has placed a significant cognitive burden on nearly all scientific texts, which has further complicated the transfer of information in fields that already require specific knowledge. Resolving this issue will however require editors with working knowledge of (various) scientific fields, as well as graphic design principles. Adding extra steps in the editing process will also cost time and effort, and therefore money, which is something no business is ever looking to do.
It is therefore unlikely that the issue of legibility in science communication, perhaps especially amongst professionals, will improve substantially over time.

Sunday 31 December 2023

Heel erg filosofisch werk

However you might feel about it, this is a simple show:

It has a front and a back, and everything you need to know about this exhibition can be found in how those two things relate to each other.

With the following three works, one can also make a simple show:

It's clear that these works are connected by a coloured rectangular element and a white, rounded, rectangular element. Each of them are also mounted on the wall at a slight angle. It then becomes an interesting search where these works deviate from this basic 'rule'.

Yet by showing these two groups at the same time, one can make an multifaceted exhibition that doesn't have any clear singular resolution:

At the surface these two groups of work appear to be very similar. They are both painted wooden objects of a similar size, in almost, but not quite, geometrical shapes.
Yet beyond that first impression, they share very few similarities. The crux of each of these works lies within their individual peculiarities, of which there is little to no overlap.
So when looking at these works altogether, there is a disconnect that you try to resolve by searching for more characteristics of these works that might tie them together. While you'll find more things that could unite them, you also encounter more individual traits that separate them. Together these two groups thus become an unsolvable problem of universals. Even if it was possible to do so seperately, once these two groups are put together, no combination of individual members is able to define the larger set.

Friday 22 December 2023

Chapter 12: Surface Tension

In 2021, after about five years of various related experiments, I started a group of work I now call γ, or gamma. This name came from the symbol physicists use for surface tension.
These works are very small watercolour paintings, of about one to three millimetres in size, framed in white frames with a white matte that has an appropriately sized cut-out at the position of the painting on the leaf.

Although these paintings are very small, the fact that they are small is by itself not what's interesting about them. What is interesting is that they are a very specific kind of small that emphasizes attributes that will only be significant at this scale.
Over the years I've developed a way of painting that gives these painted shapes a very sharp outline of about 20 to 70 micrometers thick. This is about half the width of a human hair and right on the limit of what the human eye can see. Although it is almost imperceptibly thin, this line is what gives a well defined shape and outline to what otherwise would be vague blobs that are barely distinguishable from the paper they rest on.

I had a hypothesis about how this edge is formed which involves cohesion, or the tendency of similar molecules to 'stick together'. As paint is introduced into a water droplet, the water molecules want to stay together and so they 'push' the paint downward, where the effect of the water 'pushing' the paint down is greater in the centre than it is at the edges, resulting in more paint accumulating towards the edges of the droplet.

When I work on these paintings, I only observe them from above through a small loupe, giving me a limited view and thus limited information about what is actually happening inside the droplet. In order to test my hypothesis, I therefore decided to record the process under about 10x magnification. For reference, the brushtip in the following pictures is about 0,4 mm in diameter, making the droplets about 1,5 mm wide. In this process I observed two major things that happened that seemed to be in opposition with each other:

The first thing I observed is what I naively expected to happen. When watercolour paint, itself a suspension of pigments in a solution of water and gum arabic, enters into an existing droplet of water it kind of sinks to the bottom and spreads. This leaves a uniform covering of pigment on the paper that takes the shape of the droplet after it dries.
However, as can be seen in the above photographs, this mechanism also seems to leave a thin barrier of clear water at the bottom edges of the droplet. If that area contains little, if any, paint, then how can that be the part that contains a much stronger concentration of pigments after it has dried?
Clearly something else is also at work here, and one thing I noticed is that on the right side a little blob of paint doesn't seem to enter into the water droplet, but instead kind of slides down the surface of the droplet. I thought this would be caused by that part of the paint not breaking the surface tension of the droplet and thus never entering into it.

I tested this by creating another droplet with a higher contact angle, which from what I understand should increase the surface tension. While in the previous example the contact angle was approximately 60º, in this droplet it is roughly 90º.
As you can see, the behaviour of the added watercolour paint changes in this situation. The paint indeed 'sticks' more to the edges of the droplet, instead of 'falling' straight down.

A third water droplet has a contact angle of about 120º. In this larger droplet, clearly under more tension, the paint seems to stay almost exclusively at the surface of the droplet, with only a small strand of paint passing the barrier. What's interesting to note is that this strand seems to reach the centre of the droplet almost instantly and it stays connected to the rest of the paint as it glides down the side. It also does this much more quickly than the larger blob in the first example.

These are the second and seventh frame from the first and third examples. The time between these two points was 3,13 seconds in the top example and 1,77 seconds in the second. Dissolution takes time, and on such a small scale these differences can have a significant effect.

A difficulty related to documenting these phenomena is that although the previous images give a reasonable idea about the paint being on the side or on the centre of the droplet, it doesn't show what is happening at the bottom at all sides. As understanding what happens there is vital to the impact the final paintings may have, a different experimental set-up is required in future research.

Yet another aspect that has to be kept in mind with these paintings is that different pigments will have different molecular composition, which will dissolve differently in both pure water and a solution of water and gum arabic.

This is an orange pigment, which produces much more coarse flakes of pigment. It quickly sinks to the surface of the paper and doesn't move much from its inital position. What is interesting to note is that the small amount of pigment that does dissolve in the water ultimately ends up at the edge of the droplet, as can be seen in the final frame.
This effect of pigment clustering at the edges can also be seen in a different test, that had a minimal droplet volume:

After drying, this gave a nearly closed outline of the droplet, with little to no pigment in the centre:

Again, please remember that the diameter of this circle is only about 1,5 mm.
Although these observations have given me some insights into the behaviour of the paint when introduced to a droplet of water, the system is in constant motion and dependent on many variables. It takes anywhere from a few minutes to an hour for a droplet to fully dry, so there is plenty of opportunity for the paint to dissolve and move about.

This sequence shows the full drying process. The first six images span the first few seconds and the last six images comprise about a minute. The three middle images on the other hand are about fifteen minutes apart.
The last few images also clearly show a strong interaction with the fibres of the paper, something that hasn't yet been considered in the previous images.

Since making these images I have continued to create some paintings, with some experiments using varying temperatures, separating differently coloured pigments inside one droplet and controlling the exact shape and intensity of the 'ring' at the edge of the droplets.
Yet further research is still warranted. As it is a system that is constantly in motion, there are many variables and the accompanying theory is complex, with observations from one instance not necessarily carrying over to another. Important variables like pigment and paint composition, paper structure, temperature, drying time and methods for introducing the paint are not yet mapped.
All of this also doesn't say anthing yet about the artistic effects that could be obtained after the mechanisms are properly understood and can be predictably deployed.
Even though I have been working on it on some way for the past two years, I thus feel like my knowledge about the subject is still in its infancy.