This is my first attempt at designing a lighted frame box for displaying 3D-printed lithophanes. It has three 50x80mm openings and one 164x80mm opening. Lithophanes to fit should be printed at 53x83mm and 167x83mm, all 1.5mm thick. The lithophanes mount in an insert which fits inside the front of the case; a front panel snaps on to hold the lithophanes in place. It's easy to swap out lithophanes by flexing the front panel slightly and removing it.

EDIT 2/4/18 - I've been experimenting with different thicknesses of lithophane ... 1.5mm is a little thin, and results in more visible artifacts because you don't have all that many 'shades of grey'. I've been getting better results with slightly thicker lithophanes - 2 or 2.5mm. You just need to make sure the outer 1.5mm of each lithophane is not too thick, so that they fit beneath the front frame. I've been getting good results by printing at 2.5mm, with a 60% gray border (1.5mm wide) in the original photo so that the outer edge of the final lithophane is less than 2mm thick.

Monoprice Maker Select V2

Doesn't Matter

Yes

You may need to rotate the mounting insert and front panel before printing; the front panel should be printed with supports. The front panel STL file includes decorative 1mm 'trenches'; it should be possible to switch filaments if you like so the bottoms of the trenches are a different color from the rest of the panel (I haven't had a chance to do this yet but will post a photo once I do - the photos of the front panel currently posted are from a previous version, which did not have the trenches). The rear panel is attached with M3 screws.

EDIT 2/3/18 - I added a rear support that allows you to set the frame at a range of angles - you need an M3 bolt (10mm or 12mm) and nut to attach the lower adjustable strut. I didn't include holes in the back panel to attach the support, so you would need to drill holes to attach the support if you want to use it.

Requires an LED self-adhesive strip (e.g. https://www.amazon.com/gp/product/B01FHNJUGO/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1), mounted around the inside of the case. There is a 14mm x 28mm cutout in the rear panel for a rocker switch (https://www.amazon.com/Gardner-Bender-GSW-41-Appliance-Rocker/dp/B000BVZBPW/ref=sr_1_1?ie=UTF8&qid=1517506510&sr=8-1&keywords=Gardner+Bender+gsw-41). I glued a piece of aluminum foil to the inside of the back panel to direct the light forward to illuminate the lithophanes.