Children's Day is one of those occasions where handmade gifts hit differently. A store-bought pencil box is forgotten by December. But a shiny resin keychain with a child's favourite colour swirled inside it? That stays on their school bag for months. Pair it with a matching resin bookmark and you have a gift set that looks premium, costs very little to make, and can be produced in bulk over a single weekend.
The secret to pulling this off without losing your mind is the right mould. The 9 Cavity Rectangle Pendant/Keychain Mould lets you cast nine identical pieces in one pour. Use two pours — one for keychains, one for bookmarks — and you have eighteen finished pieces ready to sand, seal, and gift-wrap before Sunday evening. That's the kind of efficiency home sellers and craft enthusiasts dream about.
This guide walks you through every step: materials, mixing ratios, colour ideas kids actually love, demolding without breakage, and finishing touches that make the set look like it came from a boutique. Whether you're making ten sets for a classroom or thirty for a small Children's Day pop-up, this process scales cleanly.
Quick Answer: What You Need to Know First
Before we get into the details, here's the short version for those who want to jump straight to casting:
- Use the 9 Cavity Rectangle Pendant/Keychain Mould — it gives you nine pieces per pour.
- Epoxy resin (1:1 or 2:1 ratio) works best for keychains; UV resin works if you want same-day results.
- Mix resin for 3–4 minutes, add mica pigment, pour, and let cure 24–48 hours before demolding.
- Sand edges with 400-grit, then 1000-grit. Apply UV resin or varnish as a top coat for gloss.
- Add keychain rings and bookmark tassels to finish the set.
- Two pours on Saturday + finishing on Sunday = ready-to-gift sets by Sunday evening.
Why the 9-Cavity Rectangle Mould Is Perfect for This Project
Most pendant moulds give you one to four cavities. That's fine for one-off pieces, but it's painfully slow when you need to produce gifts in quantity. The 9-cavity rectangle format changes the math entirely.
Each cavity in the mould produces a slim, flat rectangle — the ideal shape for both a keychain pendant and a bookmark. The dimensions are compact enough to fit on a school bag clip but substantial enough to hold embedded glitter, dried flowers, or alphabet stickers inside the resin. No awkward trimming, no shape mismatch between the keychain and the bookmark.
The silicone is food-grade flexible, which means you can pop pieces out without cracking them — a genuine concern with rigid moulds when you're working fast. Compare this to the Rectangle Cubic 20mm Deep Casting Mould (4" x 2"), which is excellent for thick statement pieces but produces one large slab you'd need to cut and drill — far more work for a batch project.
For keychains specifically, the flat profile also means less resin per piece, which reduces cost per unit — important when you're making thirty or forty sets.
Complete Materials List
Gather everything before you start. Running out of hardener mid-mix is the most avoidable disaster in resin art.
- 9 Cavity Rectangle Pendant/Keychain Mould — one mould handles nine pieces per pour
- Epoxy resin and hardener — 1:1 or 2:1 ratio depending on your brand (check the label)
- Mica pigment powders — 2–3 colours per batch; pearl white, rose gold, and teal are crowd favourites for kids
- Silicone mixing cups — reusable and easy to peel clean
- Wooden or silicone stir sticks
- Isopropyl alcohol (IPA) 99% — for surface prep and bubble popping
- Heat gun or lighter — to pop surface bubbles after pouring
- Glitter, dried flowers, or small alphabet stickers — embeds for personalisation
- Sandpaper — 400, 800, and 1000 grit wet-dry sheets
- UV resin or glossy varnish — for the final top coat
- Keychain rings and jump rings — 20–25mm rings work well
- Bookmark tassels — available at stationery stores or online
- Drill with 1.5mm bit — to add the hanging hole if the mould doesn't include one
- Nitrile gloves and a respirator mask
Choosing Between UV Resin and Epoxy Resin
This is the question every beginner asks, and the answer depends on your timeline and workspace. Our detailed comparison at UV Resin vs Epoxy Resin for Small Moulds: Which One Actually Works Better for Keychains, Pendants, and Jewelry in Indian Humidity? covers this thoroughly, but here's the summary for this specific project:
| Factor | UV Resin | Epoxy Resin (2-part) |
|---|---|---|
| Cure time | 2–5 minutes under UV lamp | 24–48 hours at room temperature |
| Batch suitability | One cavity at a time (lamp coverage) | All 9 cavities in one pour |
| Clarity | Crystal clear | Clear, may yellow slightly over months |
| Cost per pour | Higher per gram | Lower per gram for bulk |
| Humidity sensitivity | Low | Moderate — avoid monsoon humidity above 80% |
| Best for | Same-day gifting, small quantities | Weekend batch production, 10+ sets |
For a Children's Day batch of 20–30 sets, epoxy resin is the more practical and economical choice. If you're unsure about mixing ratios, read our guide on How to Choose the Right Resin Ratio for Your First Project: 1:1 vs 2:1 Explained for Indian Beginners before you open your first bottle.
Colour and Embed Ideas Kids Will Love
Children's Day gifts need to feel fun and a little bit magical. Here are combinations that consistently work well:
Colour Palettes That Sell
- Rainbow swirl — pour three colours (red, yellow, blue) and swirl with a toothpick. Each piece comes out unique.
- Galaxy theme — dark navy base with silver and purple mica, plus holographic glitter. Looks stunning and photographs beautifully.
- Pastel dream — soft pink, mint, and white swirled together. Popular with girls aged 6–12.
- Ocean blue — teal and white with a tiny shell or blue glitter embed.
- Gold and white — pearl white base with gold mica streaks. Looks premium without extra cost.
Embeds That Work in Rectangle Cavities
- Dried flowers (pressed chamomile or rose petals)
- Holographic glitter flakes — add after the first thin layer sets slightly
- Small alphabet stickers spelling the child's initial
- Tiny star or heart confetti
- Gold leaf flakes for a festive look
Keep embeds flat and lightweight. Heavy or bulky embeds sink to the bottom of the cavity and end up on the front face of the piece — which can look unintentional unless you plan for it.
Step-by-Step: Casting the Keychain and Bookmark Set
Day 1, Morning — First Pour (Keychains)
Step 1: Prep your workspace. Lay the mould flat on a level surface. Wipe each cavity with a dry cloth. Uneven surfaces cause one side of the piece to be thicker — annoying to sand later.
Step 2: Measure your resin. For nine cavities in this mould, you'll need roughly 15–20ml of mixed resin total (Part A + Part B combined). Measure by weight on a kitchen scale for accuracy. A 1:1 ratio means equal weights of resin and hardener. A 2:1 ratio means twice as much resin as hardener — always check your specific brand's instructions.
Step 3: Mix slowly. Stir for a full 3–4 minutes, scraping the sides and bottom of the cup. Undermixing is the number one cause of sticky, uncured resin. If you've had this problem before, our article on Why Your Resin Is Still Sticky After 24 Hours — and How to Fix It Before You Ruin the Piece explains exactly what went wrong and how to salvage it.
Step 4: Add colour. Split your mixed resin into two or three small cups. Add a pinch of mica pigment powder to each — about 2–3% by weight is enough for vibrant colour. Stir each colour cup for 30 seconds.
Step 5: Pour. Fill each cavity to about 80% full. Then add your colour swirls — drop the second colour in and drag a toothpick through both colours in a figure-eight motion. Add glitter or dried flowers now if using.
Step 6: Pop bubbles. Pass a heat gun or lighter quickly over the surface — 2–3 seconds per cavity, keeping the flame at least 10cm away. Bubbles will rise and pop within seconds. Don't linger; too much heat warps the silicone and causes the resin to yellow.
Step 7: Cover and cure. Place a box or container over the mould to keep dust off. Leave undisturbed for 24 hours at room temperature (ideally 25–28°C). In Indian summers, work in an air-conditioned room if possible — high ambient heat speeds up the reaction and can cause cracking in thick pours. See our notes on Deep Pour vs Thin Pour Epoxy in Indian Summers: Why Your Resin Overheats in May and What to Do About It for more on managing heat.
Day 1, Afternoon — Second Pour (Bookmarks)
While your keychain pieces cure, do a second pour in the same mould for the bookmark pieces. Use a complementary colour palette — same base colour but a different accent — so the set looks coordinated without being identical.
Bookmarks benefit from a slightly thicker pour (fill to 90% of the cavity depth) for a sturdier feel. The rectangle shape naturally suits bookmark use — slim enough to sit between pages without bulging the book.
Day 2, Morning — Demolding and Sanding
Demold gently. After 24–48 hours, flex the mould from the back and push each piece out from the bottom. Don't pull from the top or you risk snapping a thin piece. If a piece resists, leave it another 4–6 hours.
Sand the edges. Fresh resin pieces have a slightly rough edge from the mould seam. Start with 400-grit wet-dry sandpaper (keep it wet), then move to 800-grit, then 1000-grit. This takes about 2–3 minutes per piece. The surface will look cloudy after sanding — that's normal and expected.
Apply a top coat. Brush a thin layer of UV resin over each piece and cure under a UV lamp for 2–3 minutes. This restores the glass-like gloss and protects the surface from scratches. Alternatively, use a glossy resin varnish and let it air-dry for 30 minutes.
Batch Production Tips for a Weekend
Making 20–30 gift sets in a weekend is completely doable if you plan your pours in sequence rather than doing everything at once.
- Do two pours per day. Morning pour at 8am, second pour at 2pm. Both cure overnight. By Sunday morning you have four batches of nine pieces each — 36 pieces total.
- Label your batches. Use small sticky notes under each mould. Colour name + pour time. You'll thank yourself when you're sorting 36 pieces on Sunday morning.
- Prep your hardware in advance. Open all keychain rings and lay out tassels before you start sanding. Assembly goes much faster.
- Work in a clean, enclosed space. Dust and pet hair are the enemy of clear resin. Close windows if you're near a construction site or a dusty road.
- Use silicone cups for mixing. Cured resin peels right out. You can reuse the same cups all weekend without buying disposables.
If you want to expand your mould collection for future batches, the Round Pendant Mould pairs well with the rectangle set — round pieces work as earring drops or bag charms to complete a larger gift bundle.
Finishing, Hardware, and Packaging
Adding the Keychain Hardware
Most rectangle pendant moulds include a small hole at the top of each cavity. If yours doesn't, use a 1.5mm drill bit to create a clean hole 3–4mm from the top edge. Drill slowly and keep the piece flat — rushing causes chipping.
Thread a jump ring through the hole, close it with flat-nose pliers, then attach the keychain ring. Done. The whole process takes under a minute per piece once you get a rhythm going.
Adding the Bookmark Tassel
For bookmarks, skip the keychain ring. Instead, thread a decorative tassel (15–20cm long) directly through the jump ring. Metallic gold and silver tassels look especially polished against jewel-toned resin. You can find these at craft stores or order in bulk online.
Packaging for Gifting
- Place each set (one keychain + one bookmark) in a small zip-lock bag or a kraft paper envelope.
- Add a small card with the child's name handwritten — personal touches matter for gifting.
- Tie the envelope with a ribbon in the same colour as the resin set.
- If selling, add a care card: "Avoid prolonged water exposure. Wipe clean with a dry cloth."
Safety Notes
Resin is safe to work with when you take basic precautions. Don't skip these steps, especially if children are nearby during production.
- Always wear nitrile gloves. Epoxy resin can cause skin sensitisation with repeated bare-skin contact. Latex gloves are not adequate — resin penetrates them.
- Work in a ventilated space. Open a window or use a fan pointing outward. Epoxy fumes are low-level but accumulate in small rooms.
- Wear a respirator mask rated for organic vapours if you're doing multiple pours in one session.
- Keep children away from the workspace during mixing and pouring. Cured resin is non-toxic and safe to handle.
- Store resin bottles upright in a cool, dark cupboard. Heat degrades the hardener and causes premature yellowing.
- Dispose of mixing cups responsibly. Let any leftover mixed resin cure fully in the cup before throwing it away — liquid resin should never go down the drain.
Frequently Asked Questions
How much resin do I need for one full pour in the 9-cavity rectangle mould?
Roughly 15–20ml of mixed resin (Part A + Part B combined) fills all nine cavities comfortably. Mix about 25ml to account for the resin that sticks to the mixing cup walls. If you're doing four pours over a weekend, prepare at least 100ml of mixed resin total, or about 50ml each of Part A and Part B for a 1:1 ratio product.
Can I use this mould for both keychains and bookmarks in the same pour?
Yes. The rectangle shape works for both. The only difference is the hardware you attach after curing — a keychain ring for one, a tassel for the other. You can pour all nine cavities with the same colour and decide later which pieces become keychains and which become bookmarks based on how they turn out.
My resin pieces came out cloudy after demolding. What went wrong?
Cloudiness after demolding is almost always caused by moisture — either from humidity in the air or from condensation on the mould surface. Wipe your mould dry before pouring, and work in a room with humidity below 70%. Cloudiness can also come from undermixing. A top coat of UV resin or glossy varnish will restore clarity in mild cases. For persistent stickiness or cloudiness, check our article on Why Your Resin Is Still Sticky After 24 Hours — and How to Fix It Before You Ruin the Piece.
How do I make the keychain and bookmark set look matching without being identical?
Use the same base colour for both but vary the accent. For example: pearl white base with gold swirls for the keychain, and pearl white base with rose gold swirls for the bookmark. Same family, different personality. You can also use the same colours but reverse the ratio — more gold in the keychain, more white in the bookmark.
Can children help make these resin gifts?
Children aged 14 and above can help with supervised tasks like adding glitter to poured resin or attaching hardware to cured pieces. Mixing and pouring epoxy resin should only be done by adults because of the fumes and sensitisation risk. UV resin is slightly safer for supervised older teenagers but still requires gloves and ventilation. Finished, fully cured resin pieces are completely safe for children of all ages to handle and use.
How long do these resin keychains and bookmarks last?
With a proper top coat applied, epoxy resin keychains and bookmarks last several years under normal use. Avoid leaving them in direct sunlight for long periods — UV exposure causes yellowing over time in standard epoxy. If you use a UV-resistant epoxy or apply a UV-protective varnish as the top coat, the pieces stay clear much longer. Keep them away from prolonged water exposure; the resin itself is waterproof but the metal hardware can rust.
What other moulds work well alongside the 9-cavity rectangle for a Children's Day gift set?
The Round Pendant Mould is a natural companion — round pieces work as bag charms or earring drops to expand the set. For larger classroom or school gifts, the 8" Square Plain Mould produces coaster-sized pieces that can be gifted as desk mats or photo frames with a little extra effort.
Wrapping Up
A matching resin keychain and bookmark set is one of those gifts that punches well above its cost. It looks handcrafted because it is — and children can feel that difference. The 9-cavity rectangle silicone mould for resin makes the whole thing scalable: nine pieces per pour, two pours per day, a full weekend of production gives you enough sets for an entire classroom or a small Children's Day sale.
The process is forgiving once you nail the basics — accurate measuring, thorough mixing, and patience during curing. If you want to explore more creative mould options for seasonal projects, our guide on Creating Unique Monsoon Decor: A Step-by-Step Guide to Using Silicone Molds with Resin has ideas that translate well to festive gifting too.
Pick up the 9 Cavity Rectangle Pendant/Keychain Mould from Shrebhavi, gather your mica pigments and epoxy resin, and set aside a weekend before Children's Day. The kids who receive these will remember them long after the holiday is over.