◆ Resin
Alphabet resin keychain mold, S to Z and &
Eight bubble letter keychains, S to Z, and an ampersand, each with a key ring hole. Finishes the resin alphabet.
◆ Resin
Eight bubble letter keychains, S to Z, and an ampersand, each with a key ring hole. Finishes the resin alphabet.
A silicone mold for S, T, U, V, W, X, Y and Z plus an ampersand, in a rounded bubble typeface 35 mm tall and 5.5 mm thick. The ampersand makes couple keychains (A & J) and wedding favours without a fourth tray. Each shape has a round tab with a post in the cavity, so every piece comes out with a 3.8 mm hole for a jump ring.
Made with our tray mold generator in its flexible silicone tray mode: print one part, a caster, pour a platinum silicone into it and peel it out. That silicone is the resin mold, and resin lets go of it with a glossy face and no release agent. The set of nine takes about 45 ml of resin.
Where a letter has no flat top in the middle (U, V, W, X, Y), the tab sits on the arm nearest the letter's balance point, so it hangs as straight as the shape allows. This is the last of three trays (A to I and J to R are separate designs, and there is a 0 to 9 number tray). The zip carries the printed caster exactly as the tool exported it, the nine pieces on their own as an STL, the master uploaded to the tool, and a print and pour sheet with the silicone figure the tool measured.
Shown as a 3D render of the printed caster with the nine lilac resin letters in front, not a photo.
Print the caster as exported, open side up, no supports. Turn on ironing for the top surfaces, or sand the raised shapes smooth and brush on XTC-3D: the silicone copies every layer line, and resin shows each one on its glossy face.
Mix 207 ml of platinum silicone and pour it into one corner of the caster in a thin stream until it covers the shapes to the rim. Tap out the bubbles, let it cure as long as its datasheet says and peel it out. That silicone is your resin mold: platinum silicone gives resin a glossy face and needs no release agent.
Work in a ventilated room with nitrile gloves on. Mix epoxy casting resin exactly at the ratio on the bottle, stir slowly for three minutes scraping the sides, and let it rest a few minutes so the bubbles rise.
Glitter, mica or dried flowers go in face down: the side against the silicone is the front. Fill each cavity to just below the top of its post (all nine pieces take about 45 ml together) so the hole stays open, and pass a heat gun or a lighter quickly over the surface to pop the bubbles. Cover the mold against dust.
Leave epoxy 24 hours (UV resin: cure each layer under the lamp), then flex the mold and peel it off the pieces rather than pushing them out. Let epoxy harden two more days before you fit jump rings, hooks or a tassel.
Print details
| Cast material | Resin |
|---|---|
| Printed parts | 1 |
| Size (W x D x H) | 145 x 153 x 18 mm |
| Print bed needed | 153 x 146 mm, 18 mm tall |
| Filament | ~88 g |
| Layer height | 0.2 mm |
| Infill | 15% |
| Supports | Not needed |
| Download | ZIP: printed caster (STL) + one set of eight letters and an ampersand (STL) + tool master (STL) + print and pour sheet |
| Added | 2026-09-27 |
Pro early access until October 27, 2026, then free with any account.
Like it or post your print on Thingiverse
Make your own tray mold →Made with the free Tray mold generator. Upload your own model and get the same kind of mold built around it, in your browser.
Free for personal use. Selling the pieces you cast needs a commercial licence (Pro or Founder); passing on the file itself is not permitted on any plan. Full terms.
New to casting? Read the ice cube tray mold guide.
Cast the two initials from their trays and the ampersand from this one, then link them with 6 mm jump rings through the tabs, or hang all three from one split ring. A clear ampersand with gold leaf between two coloured letters reads well from a distance.
Those letters dip in the middle, so a tab there would hang on a thin point or bridge an empty notch. The tab sits on the arm nearest the letter's centre of weight instead, where the resin is thick, so the letter hangs close to straight and the hole never tears out.
A clear epoxy casting resin with a 24 hour demold is the easiest: it fills the 5.5 mm depth in one pour and cures hard. UV resin works in two layers of about 3 mm, each cured under the lamp, and is quicker for one or two letters. Avoid thin coating resins, which stay soft in a pour this deep.
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