◆ Resin

Resin bookmark mold, 4 shapes

Four resin bookmarks per pour: rectangle, arch, ribbon tail and capsule, each with a tassel hole.

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3D render of the printed caster for a resin bookmark mold with four shapes, and four lilac resin bookmarks with tassel holes in front
Resin ~129 g Pro early access

A silicone mold for four resin bookmarks, each 40 x 150 mm and 4 mm thick: a rounded rectangle, an arch, a ribbon with a swallowtail end and a capsule with two round ends. A post near the top of every cavity leaves a 5 mm hole for a tassel or a ribbon, so nothing needs drilling.

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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 bookmark mold, and resin lets go of it with a glossy face and no release agent. All four bookmarks take about 90 ml of resin together.

Pressed flower bookmarks are one of the most popular resin gifts, and a thin, flat cavity is where a flower lies best. Fill to just below the top of the tassel post. The zip carries the printed caster exactly as the tool exported it, the four bookmarks 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 a set of four lilac resin bookmarks in front, not a photo.

Resin bookmark mold, 4 shapes at a glance: every printed part with its size, print time, filament, print settings and the three steps to use it

What you need

4
  • About 379 ml of platinum silicone (mix it in one batch)
  • About 90 ml of clear epoxy casting resin or UV resin for all four
  • Pressed, fully dried flowers and leaves, or a printed quote sealed with Mod Podge
  • Tassels or ribbon, nitrile gloves, tweezers and a heat gun

How to cast it

5

  1. 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.

  2. Mix 379 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.

  3. 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.

  4. Lay pressed flowers face down in a thin first layer so they sit at the front, then fill. Fill each cavity to just below the top of its post (all four bookmarks take about 90 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.

  5. 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

4 h 20 minPrint time
~129 gFilament
1Printed parts
191 × 161 × 16 mmSize (W x D x H)
All print details
Print details
Cast materialResin
Printed parts1
Size (W x D x H)191 x 161 x 16 mm
Print bed needed192 x 162 mm, 17 mm tall
Filament~129 g
Layer height0.2 mm
Infill15%
SupportsNot needed
DownloadZIP: printed caster (STL) + one set of four bookmarks (STL) + tool master (STL) + print and pour sheet
Added2026-09-27

Pro early access until October 27, 2026, then free with any account.

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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.

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Questions about this design

How do I stop pressed flowers floating in a resin bookmark?

Pour a 1 mm layer of clear resin, let it gel for 30 to 60 minutes until it is tacky, then lay the flowers face down on it with tweezers and fill the rest. The gelled layer holds them in place. The flowers must be completely dry, or they brown and bubble in the resin.

Why is my resin bookmark bent after demolding?

At 4 mm a bookmark is still flexible for a day or two after it comes out. Demold after 24 to 48 hours, lay it flat on a smooth surface under a light book for another two days, and it hardens straight. A bookmark that is still bendy after a week was mixed off ratio.

Can I use UV resin for the resin bookmark mold?

Yes, and it suits the thin 4 mm cavity: pour two layers of about 2 mm and cure each under a UV lamp for the time on the bottle. Pressed flowers go between the layers. UV resin cannot cure under heavy pigment, so keep colour to tints and mica.

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