Photolithographic masks, or photomasks are clear templates used in semiconductor manufacturing. Typically, they are made of UV-grade fused silica and have a highly intricate chrome metal film pattern on one side. These remarkable objects are exactly the sort of wonderful thing that occasionally pops up at good electronics surplus stores. We recently found a few, took some pictures (see below) and, in the spirit of re-use, made them into some classy coasters.

Five inch masks are the perfect size for coasters. The components are basic: an assortment of masks and some rubber feet.

Rubber feet go on the corners of the masks on the silvered side, and that is all there is to it!

But because the photomasks are so detailed, here are some bonus pictures of the ones we’ve made into coasters.

Some of the masks look nearly transparent. Only closer inspection reveals the pattern. This particular one is for alignment and has incredibly fine detail in gridded quadrants.

This mask has an almost houndstooth pattern.

This mask has a pattern of circles on it. There are four different line weights, giving a gray scale pattern.

But when you look closer, there is much more than just circles. This photo was taken with the mask right up against the camera lens.

When you look even closer, as in this cropped version, the Agilent logo becomes visible. Just for reference, those big circles on the sides are one-eighth of an inch in diameter.

There are large versions of these pictures and more close-ups of these masks in this set for your enjoyment.

So, keep your eyes open for photomasks when you’re out shopping. They’re lovely things to have around, and can even be useful, too.