So I've been wanting to make those Clear Keychains for some of my Artist Friends that we saw at a Convention, with my first idea being Resin 3D Printing, a thing that I am very much unfamiliar with!
My Idea is to 3D Print out a Transparent shape, then Print the same shape but mirrored, then take both and Sandwich a Paper Print picture of one of my Friends Characters between the 2 and bind it all together!
There is a concern that I have Before I go out and get myself setup with a Resin 3D Printer... how Clear is Clear Resin anyway? All I can seem to find Online is Prints made by the Resin Sellers, which lets be real, cannot be trusted on its own. Given that the Paper Picture Sandwiched in the 2 Resin Shapes needs to be very Visible, the Resin Shape must be basically Near Perfectly Clear. What is your Folks experience with Clear Resin? Would you recommend using a Resin 3D Printer for this or should I go look for other Methods?
Edit: Thanks too all of you for shimming in with your Many Detailed Experiences, Ideas and Suggestions! After considering everything, I've decided that the best Route I should take is utilising a Laser Cutting Machine with Acrylic. A thing I've somehow not considered before! I want to choose the Lasercutting method in Particular as I think it'll also allow for many other Possibilities to Create things in the Future! Now I do have to do my Research on what machines are on the Market for Transparent Acrylic, as from what I've read only certain Laser Types can Handle those. But I think I'll find something that Suits me! Much thanks for everyone who Commented here!
It is really difficult to get consistent optical properties using additive manufacturing techniques. There's a reason optics (lenses, etc) are basically universally made from uniform pieces ground down and polished smooth, and compound lenses are avoided unless absolutely necessary and to make them optically clear enough requires exceptionally complex and expensive methods. With typical additive manufacturing, you are making something that is basically hundreds or thousands of compound lenses stacked onto each other, and the optics are always going to be pretty awful no matter how much care you put into the process. There is no easy answer, except to not use additive manufacturing for this. For optical properties, you really want to stick to a single shot of consistent material as much as possible, to minimize internal refraction (which happens at every material surface transition if it's not perfect, which it won't be). Cutting material away is fine, you're getting rid of the old surface transition and creating a new one, you always have to interface with the outside air at some point, and that's the minimum number of refraction layers you're going to get. Adding material to it creates another layer of internal refraction for the light, making many of those is very not good.
While there are people working hard to make additive manufacturing methods that can do this as well as possible, and in a few cases they've gotten quite impressively good at it, they're still starting from a compromised beginning, the deck is stacked against them and it really is a challenge. If at all possible, don't use additive manufacturing for this. It's the wrong process for the job. The traditional approaches of molding or cutting or machining or polishing to create the shape you want, is the right way to do it. If you really need something unique you may have few good choices, but if you can get something off the shelf, it'll save you a world of headache. This is only something worth doing for the challenge of it, and you should go in with the expectation of failure, and prepared for joy if you succeed, and I'll be happy to know that you've proven me wrong.