Summary Make the perfect gift for Grandma! Upload any image and make your one-of-a-kind ornament for use with standard holiday light sets! How cool is that? Note: If you are using words in your image, make sure to reverse the image before uploading so the letters are not backwards. To you help print in different colors I made a plastic opacity test print. See instructions for more details. NOTE- I have some detailed image prep notes in my instructable here: http://www.instructables.com/id/Custom-Glowing-3D-Printed-Ornaments/ also to help educate your friends and family, best I have found under 2 minute slightly amusing, simple & straight forward explanation of home 3D printing, (made by and for schools): http://www.youtube.com/watch?v=YpHv19jdloI Instructions Open in customizer, upload image, change any setting you want, download and print. Not sure how many layers to use with a certain color? NO WORRIES! I made an opacity test strip for you! lithopane-test_opacity_3mm.stl Slice at 0.1mm layer height, 100%fill and print. Each row is a 0 - 10 layer opacity scale. Hold it up to the light to see at which thickness the light stops passing through. I made it go all the way to 3mm thick since some of the transparent plastic colors would be able to go that far. lithopane-test_opacity_3mm.stl file NOTE- I have some detailed image prep notes in my instructable here: http://www.instructables.com/id/Custom-Glowing-3D-Printed-Ornaments/