ive done this research for a project and this is what i found:

Clear resin can be transparent, but “perfectly glass-like” out of the printer is a myth. Here’s what you should expect:

Raw Print Clarity

• Most SLA/DLP clear resins come out looking cloudy or frosted. Layer lines scatter light, and the cured surface tends to have a slight haze.
• Even high-end resins that advertise “water clear” need careful handling—straight off the printer they’re closer to frosted acrylic than window glass.

Post-Processing is Everything

• Sanding & Polishing: If you sand through grits (400 → 3000) and then buff/polish, you can achieve near-crystal clarity, especially on flat faces.
• Clear Coating: Spraying or dipping in clear acrylic or epoxy can restore transparency and give a smooth finish without hours of polishing.
• UV Over-curing: Too much UV exposure yellows resin and makes it cloudy. You’ll want just enough to finish curing.
• Surface Orientation: The side that prints directly against a smooth FEP or a glass plate can come out very clear—almost lens-like—while support-touching surfaces will be rough and need finishing.

Practical Reality for Your Project

If you sandwich a printed photo between two unpolished clear resin halves, the picture will likely look murky, as if behind frosted glass. If you’re willing to polish the inner faces, you’ll get a much cleaner look—but alignment and dust control will be tricky.

For something like keychains, most makers actually skip the “clear 3D print” route and:

• Use UV-curable dome resin (like jewelry makers use) poured into bezels or molds. Much easier to get crystal clear and bubble-free.
• Or laser-cut acrylic, which is optically clear and needs no polishing. You can sandwich artwork between two acrylic pieces and bond with clear adhesive.

Recommendation

Resin 3D printing can work, but only if you’re ready for a lot of sanding, polishing, and sealing. If your main goal is crisp visibility of the artwork, poured resin or acrylic sheets will get you there faster and with more reliable clarity. The printer route shines more when you want unusual shapes or embedded 3D geometry.