Friday 22 December 2023

12800-25600 DPI

In the previous post it is mentioned that the paintings are given their distinctive appearance due to the sharp outlines of the shapes, which are about 20 to 70 micrometers in width. What I didn't describe there is what kind of consequences this has for the reproduction of these works.

Although we don't often think of them that way, digital printing and display technology always work with discrete dots. These dots are droplets of ink in printing and pixels in electronic displays. The maximum attainable resolution depends on the amount of these dots one can fit next to each other. This is usually measured in dots per inch (DPI) for printing and pixels per inch (PPI) in electronic displays. For example, Apple's top of the line 6k Pro Display XDR has a PPI of 218. This means it can fit 218 pixels on a one inch line. The minimum width it can display with a single pixel is thus 117 micrometers.
117 micrometers is already almost double of the thickest part of the outlines in the paintings. And that would just be a single, straight line. To capture at least some of the nuance in the subtle changes in shape and colour, you would require the width of a painted line to span at least 10 pixels or so. This in turn would require the space between pixels to be 1-2 micrometers, which translates to 12800-25600 DPI.

With the current technology this is simply unatainable. For comparision, this would mean that a 1920x1280 full HD screen would measure about 2 by 3 millimeters.
Current inkjet printers top out at about 1280 DPI, or 1/10th of the minimum required resolution. Laserprinters fare somewhat better at about 2400 DPI, but this is still only a fifth of what one would need to display the shape of the line acurately in a single colour of ink.
As physical limitations, as well as practical limitations of potential uses, aren't going to change drastically in the near future, it will very likely always remain impossible to accurately reproduce these paintings in print.
There is some hope for electronic displays, however. While general-purpose displays tend to reach only about 200 PPI, Sony is currently producing high resolution OLED micro displays. They are used in electronic viewfinders, VR headsets and other applications where viewers' eyes are only a few centimeters removed from the screen. Sony's highest resolution offering presently reaches 4031 PPI, or about 6,3 micrometers per pixel. While still not able to display much nuance, at least they would be able to accurately display the general width of the outline.
Presently it's thus unfortunately physically impossible to reproduce these works at their actual scale.

As the argument for this has been somewhat mathematical, I'll also try to make a more visual demonstration of this impossibility. The following illustration shows a 200 PPI 4 by 3 pixel grid, with the  the red, green en blue subpixels clearly visible. Overlaid on this image is the outline of a small painting at approximately the same scale.

In order to get a sense of how much detail is present in these paintings, the following image is an all-red pixel grid that also measures 4 by 3 pixels, which may render only as an empty thumbnail if you're reading this on a phone: