Customize a standard US switch/outlet plate of up to 5 gang with the ability to select for each slot a flip-switch, GCFI/rocker switch, traditional outlet, or blank. You can also reposition the holes in case one of the boxes isn't aligned with the others (position, not angle), and you can make the plate larger if you like. Typically you will print this face down.

There's an option to round the corners of the plate as opposed to having a "plateau" shape as shown in the illustration. It may be slow. You might not want to print that face down because the edges might not look so pretty where the supports touched them, but of course if you print it face up you'll have lots of supports on the back. It's your call.

I looked up the standard dimensions for these plates online, so this should all be accurate. I did it initially because I had an application for it -- an open electrical box that I couldn't cover with any part from the DIY because the boxes weren't lined up properly. But I realized that if you have an unusual combination of things next to each other, or just want a fun color, it's hard to buy that pre-made also.