ptpx 2025

#PlotterArt post cards for the 2025 Plotter Postcard Exchange

It's time to start on the post cards for Paul Butler's #ptpx plotter art postcard exchange. This year I've signed up for 12 recipients and I'm taking advantage of the Netherlands' December Zegels which are reduced rate postage for the winter. For sending to the buitenlands, two stamps are required. However the stamps expire at the end of the month, so this is the first year that I've actually gotten my act together to get them out before the new year. Previous years cards are at v.st/ptpx

Twenty post cards arranged in a grid with their pens atop them

My theme this year was "falling boxes" inspired by a classic 10PRINT era art piece that did a similar thing with squares. My usual workflow for these cards is to design something in OpenSCAD, render it to STL and then use my plotter.vision tool to turn the 3D into 2D SVG files, which I can then plot using my AxiDraw and saxi.

The code for this year's design is quite short:

spacing = 1.3;
max_x=9;
max_y=6;

for(i=[1:max_x+1])
{
        for(j=[0:max_y])
        {
                translate([(i-max_x/2-1)*spacing,(j-max_y/2-1)*spacing,0])
                rotate([
                        i*j/max_y* rands(0,90,1)[0],
                        i*j/(max_x*max_y)* rands(0,90,1)[0],
                        i*j/(max_x*max_y)* rands(0,60,1)[0]
                ])
                cube([1,1,1], center=true);
        }
}

Each card is a different run with different random numbers, so they are all unique. As is typical I tried out a few different orientations and displays before settling on an almost straight-on view.

Blue postcard with drawing that starts to fade away as the pen stops drawing

I adore the Molotow "Liquid Chrome" paint pen, but it is just so frustrating to work with for plotting. Midway through every drawing it seems to start to fail and stopping to give it a good shake just doesn't work well. The real MVP (for the third year in a row!) were the Pilot G-TEC-C 0.4mm.

Red/Blue 3D glasses over a plot with red and blue lines of falling cubes

Some years ago I added the "anaglyph" mode to plotter.vision for making 3D plots, which is sort of ironic since it is about taking 3D shapes and making them 2D, only to then make them 3D again. I only plotted one of these with the two colors since each pass takes about five minutes. It is really neat to see the cubes pop out of the paper with such a low tech set of glasses.

eight stamps on postcards with fairytale stories out Het Sprookjesbos

These stamps have really beautiful images from Het Sprookjesbos, the fairy tale forest at the Efteling park. Some of them are familiar like Red Riding Hood or Rapunzel, but others are new to me like Lang Jan who has a very long neck.

Anyway the stamps expire soon, so I need to go put this big stack of cards in the brievenbus!