About this project
A test artefact, not a part: one flat board carrying the same short string at four sizes, so a font can be printed once and inspected to see at which size it stops resolving. Nothing on the board does anything; the output is the print and what you read off it.
What is on the board
A 155 by 60 by 3 plate with rounded corners, four raised text samples in a row across it, and a fixed caption under each reading LARGE, MID +, MID - and SMALL. Every sample uses the same string and the same font, and only the size differs between them. The captions are plain words, so they survive a size change, and the sample nodes are named the same way.
Controls
The font sets the typeface for all four samples at once. It is the thing the board exists to test.
The largest size (14 to 24) and smallest size (5 to 12) fix the two ends of the range, and the middle two samples are spaced evenly between them, a third and two thirds of the way down from the largest. These are the two numbers that decide whether the board tells you anything: set them wide and you get a coarse sweep, close them around the size you actually intend to use and the four samples become a fine comparison near that size. A readout lists the four sizes that result, so the printed board can be recorded against them.
The test text is the string every sample shows, up to five characters. It defaults to B8R, and the parameter asks for counter-heavy glyphs or the customer text you need to check.
Relief height (0.6 to 3) raises every sample off the plate by the same amount, so a run can be repeated at a different relief without touching the sizes.
What it does not do
There is no design check here. The board makes no claim about what will print; it only puts four sizes of one font side by side so the printed result can be judged.