If you have been making resin coasters for a while, you already know the basics work. Pour, cure, demould, sand, done. But here is the thing most resin sellers figure out only after a few months: a resin coaster set round moulds combination in three different sizes moves faster than four identical coasters in a gift box. Buyers notice the variety. It looks intentional, curated, and β most importantly β more expensive than it costs you to make.
This article walks you through exactly how to cast a mixed-size coaster set using 4", 6", and 8" round silicone moulds, from prep to packaging. We will also get into why this particular size combination works so well for gifting, weddings, and festive season sales in India, and how to price it so you are actually making money.
Whether you are a hobbyist making your first set or someone building a small resin business from home, this guide gives you the practical steps, the common mistakes to avoid, and the selling logic behind the mixed-size approach.
Quick Answer: The 4-6-8 Inch Formula
Not everyone has time to read 2,000 words before their resin cures. Here is the short version:
- Use a 4" mould for espresso cups, small candles, and decorative items
- Use a 6" mould for standard mugs, tea cups, and wine glasses
- Use an 8" mould for large mugs, pitchers, or as a centrepiece tray
- Mix all three in one set β it photographs beautifully and justifies a higher price point
- Stick to one colour palette or theme across all three for a cohesive look
- Epoxy resin at a 1:1 or 2:1 ratio (check your brand), poured at room temperature between 24β30Β°C
- Cure time: 24 hours to demould, 72 hours to full hardness
Why Mixed Sizes Outsell Matching Sets
Walk into any home dΓ©cor store and you will see this pattern everywhere β nesting bowls, stacked plates in graduated sizes, candle sets in three heights. The principle is the same. Variation creates visual interest, and visual interest converts browsers into buyers.
When someone buys a resin coaster set as a gift, they want it to look thoughtful. Four identical 4" coasters in a box look like something you grabbed off a shelf. A set with a 4", two 6" coasters, and one 8" coaster looks like someone actually considered the recipient's lifestyle.
From a practical standpoint, it also makes sense. The 8" piece works as a small tray or centrepiece. The 6" handles most mugs and glasses. The 4" is perfect for espresso cups, small candles, or even as a ring dish. Your buyer gets versatility. You get to charge more.
For Diwali, wedding season, and housewarming gifts β which are the three biggest resin gifting occasions in India β this format works especially well. People giving gifts want something that looks premium without being over the top. A mixed-size resin coaster set in a coordinated colour palette hits that mark every time.
Choosing the Right Round Moulds
The mould you pick directly affects the finish quality, the ease of demoulding, and how many times you can reuse it before it starts picking up scratches. For coasters specifically, you want a silicone mould with a smooth, flat base and straight or very slightly tapered sides.
The 4" Mould
The 4" Round Silicon Mould is the workhorse of any coaster set. It is small enough that resin volume stays manageable β you are typically working with 40β50ml of mixed resin per pour. This makes it ideal for experimenting with alcohol ink designs, pigment swirls, and inclusion work without wasting expensive materials.
Because the surface area is smaller, heat buildup is also lower, which means fewer bubbles and less risk of the resin yellowing from exothermic reaction. Great starting point for beginners.
The 6" Mould
This is the most-used size in a coaster set. Most standard mugs and glasses sit comfortably on a 6" coaster. You have two good options here depending on the look you want.
The 6" Round Silicon Mould gives you a clean, flat surface β perfect for solid colour pours, geode designs, or anything where the resin itself is the star. If you want more texture and a natural stone effect right out of the mould, the 6" Zigzag/Agate Round Mould adds a built-in agate-style border that looks stunning with translucent resin and metallic pigments.
The 8" Mould
The 8" Round Silicon Mould 15MM Deep is the anchor piece of the set. At 15mm depth, it holds enough resin to feel substantial β not flimsy β and the weight gives it a premium feel when someone picks it up. This is the piece that makes buyers say "oh, this is really good quality."
Because of the larger surface area, you will need roughly 180β220ml of mixed resin for a single pour. Keep this in mind when calculating your material costs per set.
If you ever want to expand into larger statement pieces or trays, the 10" Zigzag/Agate Round Mould is a natural next step β though for a standard coaster set, the 8" is the sweet spot.
Materials You Need Before You Start
Getting your workspace and materials ready before mixing saves you from scrambling once the resin clock starts ticking. Here is what you need for one complete mixed-size set (one 4", two 6", one 8"):
- Epoxy resin β approximately 350β400ml total mixed volume
- Silicone moulds in 4", 6", and 8" sizes
- Pigment powders or alcohol inks (2β3 colours per set for cohesion)
- Mixing cups and stir sticks (at least 4 separate cups)
- Nitrile gloves, safety glasses, and a well-ventilated workspace
- Heat gun or lighter for popping surface bubbles
- Isopropyl alcohol for cleaning up spills
- Felt pads for the bottom of finished coasters
- A level surface β even a slight tilt will show in the finished piece
Before you mix anything, read up on your resin's mix ratio. Different brands have different requirements, and getting this wrong is the single most common reason resin stays sticky. Our guide on How to Choose the Right Resin Ratio for Your First Project: 1:1 vs 2:1 Explained for Indian Beginners covers this in detail.
Step-by-Step: Casting All Three Sizes
Step 1: Prepare Your Moulds
Wipe all moulds with a lint-free cloth. Check for any dust, hair, or leftover residue from previous pours. If you are using a new mould, a light wipe with isopropyl alcohol is enough. Do not use mould release spray on silicone β you do not need it, and it can actually cause adhesion problems with your pigments.
Step 2: Mix Your Base Resin
Measure resin and hardener by volume or weight according to your brand's instructions. Mix slowly for 3β4 minutes, scraping the sides and bottom of the cup. Fast mixing introduces bubbles. Slow, deliberate stirring keeps the mix clear.
For a set this size, mix one larger batch (about 350ml) and then divide it into smaller cups for colouring. This ensures all your coasters come from the same mix and have consistent clarity.
Step 3: Add Colour
Add pigment powder or alcohol ink to each smaller cup. For a cohesive set, use the same base colour in different concentrations β light in one cup, medium in another, with a metallic or shimmer accent in the third. This gives you variation without making the set look mismatched.
A good rule of thumb: pigment should be no more than 5β6% of your total resin volume. Too much pigment can interfere with curing.
Step 4: Pour in Sequence β Largest First
Start with the 8" mould. It needs the most resin and takes the longest to level out. Pour your base colour first, then add accent colours on top and use a toothpick or skewer to create swirls. Do not over-mix β 2β3 swipes is usually enough.
Move to the 6" moulds, then finish with the 4". By the time you are done with the smaller moulds, the 8" will have started to self-level and any swirl patterns will have settled nicely.
Step 5: Remove Bubbles
Pass a heat gun or lighter quickly over the surface β about 10β15cm above the resin. The heat breaks surface tension and pops bubbles. Do not hold the heat in one spot or you will scorch the resin. Two or three quick passes is enough.
If bubbles keep coming up after 20 minutes, your resin may be too cold. Resin in Indian winters (especially in North India) can get thick and bubbly if the ambient temperature drops below 22Β°C. Warm your resin bottles in a bowl of warm water for 10 minutes before mixing.
Step 6: Cover and Cure
Cover your moulds with a cardboard box or a dedicated dust cover. Do not use plastic wrap β it can sag and touch the resin surface. Leave undisturbed for at least 24 hours before attempting to demould.
Full hardness takes 72 hours. You can demould at 24 hours, but the coasters will still be slightly flexible and can warp if stacked. Leave them flat on a clean surface for the remaining cure time.
If your pieces are still tacky after 24 hours, check our troubleshooting guide: Why Your Resin Is Still Sticky After 24 Hours β and How to Fix It Before You Ruin the Piece.
Step 7: Finish the Edges
After demoulding, check the edges for any sharp flash (thin resin that seeped under the mould lip). Sand lightly with 400-grit wet sandpaper, then move to 800-grit, then 1500-grit for a polished edge. Wipe clean and apply a thin coat of resin or a resin polish if you want a glossy edge finish.
Stick felt pads on the bottom. This protects furniture and also makes the coaster feel more finished β buyers notice small details like this.
Design Ideas That Work Across All Three Sizes
The best designs for a mixed-size resin coaster set are ones that look connected but not identical. Here are a few approaches that work well:
- Gradient series: Lightest colour on the 4", medium on the 6", deepest on the 8"
- Agate theme: Use the zigzag mould for the 6" and pair it with plain pours in matching colours for the other sizes
- Monsoon blues: Teal, navy, and silver on all three β works beautifully for July-August gifting. See our guide on Creating Unique Monsoon Decor: A Step-by-Step Guide to Using Silicone Molds with Resin for inspiration
- Festive gold: Deep burgundy or forest green with gold powder swirls β ideal for Diwali sets
- Marble effect: White base with grey and black veining, gold accent on the 8" piece only
Size and Volume Comparison Table
| Mould Size | Resin Volume Needed | Best Used For | Cure Time (Demould) | Approx. Weight (Finished) |
|---|---|---|---|---|
| 4" Round | 40β55 ml | Espresso cups, small candles, ring dish | 20β24 hours | 60β80g |
| 6" Round (plain) | 90β110 ml | Standard mugs, tea cups, wine glasses | 22β24 hours | 130β160g |
| 6" Zigzag/Agate | 95β115 ml | Same as above + textured gift sets | 22β24 hours | 135β165g |
| 8" Round (15mm deep) | 180β220 ml | Large mugs, pitchers, centrepiece tray | 24β28 hours | 280β340g |
Safety Notes for Working with Epoxy Resin
Epoxy resin is safe when handled correctly, but it is a chemical and deserves proper respect. Here are the non-negotiables:
- Ventilation: Always work in a well-ventilated space. Resin fumes are not immediately dangerous in small quantities, but prolonged exposure without airflow is not good for you. Open windows, use a fan to push fumes away from your face.
- Gloves: Nitrile gloves every single time. Resin on skin can cause sensitisation over time β meaning you can develop an allergy even if you have had no reaction previously.
- Eye protection: Safety glasses when pouring or using a heat gun.
- Heat management: The 8" mould holds a lot of resin. Larger volumes generate more heat during curing. In Indian summers, this can cause the resin to cure too fast, cloud up, or even crack. Read our article on Deep Pour vs Thin Pour Epoxy in Indian Summers: Why Your Resin Overheats in May and What to Do About It before working in peak summer months.
- Children and pets: Keep uncured resin away from both. Once fully cured, resin is inert and safe.
- Disposal: Never pour liquid resin down the drain. Let any leftover mixed resin cure in a small cup, then dispose of it as solid waste.
Packaging and Gifting the Set
A beautiful coaster set in a plain plastic bag is a missed opportunity. Packaging is part of the product, especially for gifting occasions.
Basic Packaging That Works
- Line a kraft paper box with tissue paper in a colour that complements your coaster palette
- Stack the coasters with a felt square between each piece to prevent scratching
- Add a small card with care instructions ("wipe clean, not dishwasher safe")
- Seal with a ribbon or wax seal for premium presentation
Festive Season Packaging
For Diwali and wedding gifting, consider a wooden box or a cloth-covered box. The mixed-size set (one 4", two 6", one 8") fits perfectly in a standard 10"Γ10" gift box with some creative arrangement. Photograph the open box for your product listing β this image consistently outperforms a plain flat-lay of the coasters alone.
Selling Resin Coasters Online in India
The mixed-size resin coaster set format is particularly well-suited to online selling because it photographs well and has a clear value proposition. Here is what actually works:
Pricing Your Set
Add up your material costs β resin, pigments, mould depreciation (divide the mould cost by the number of pours you expect to get from it), packaging, and your time. A realistic time estimate for one set including curing and finishing is about 2.5β3 hours of active work spread across two days.
Most mixed-size resin coaster sets in India sell between βΉ800 and βΉ2,200 depending on design complexity and platform. Festive season sets with premium packaging can go higher. Price below βΉ800 and you are likely undervaluing your work.
Photography Tips
- Shoot in natural light, ideally near a north-facing window to avoid harsh shadows
- Style the 8" piece with an actual mug on top β it helps buyers understand the scale
- Show all three sizes together in one shot and then individual close-ups
- Include a lifestyle shot β coasters on a coffee table, not just on a white background
Platform Considerations
Instagram and Etsy work well for handmade resin products. WhatsApp catalogue selling is surprisingly effective in India for repeat customers and local gifting orders. If you are selling on Instagram, Reels showing the pour process consistently outperform static posts β people are genuinely fascinated by resin pours.
If you are new to working with moulds and wondering whether to use UV resin or epoxy for smaller pieces in your product range, our comparison article UV Resin vs Epoxy Resin for Small Moulds: Which One Actually Works Better for Keychains, Pendants, and Jewelry in Indian Humidity? is worth reading before you expand your product line.
Frequently Asked Questions
How much resin do I need for a complete 4", 6", and 8" coaster set?
For one set with one 4" coaster, two 6" coasters, and one 8" coaster, you will need approximately 350β400ml of mixed resin. It is always smart to mix a little extra β about 10% more than your calculated volume β to account for any that sticks to mixing cups or is used for colour testing. Measure by volume or weight depending on your resin brand's instructions.
Can I use the same design across all three mould sizes?
Yes, and it is actually recommended for a cohesive gift set. The easiest approach is to use the same colour palette with slight variations β different concentrations of the same pigment, or the same base colour with different accent placements. Identical designs on different sizes look intentional. Completely different designs on each piece can look like leftover stock bundled together.
Why is my 8" coaster cloudy but the 4" came out clear?
This usually happens due to heat buildup. Larger resin volumes generate more heat as they cure, which can cause cloudiness, yellowing, or even surface cracking. In Indian summers especially, this is a common problem. Work in a cooler part of the day (early morning), keep your workspace temperature below 30Β°C, and consider doing a thin base pour followed by a second pour once the first has gelled slightly. This spreads the exothermic reaction across two stages.
How many times can I use a silicone round mould before it needs replacing?
A good quality silicone mould can typically handle 50β80 pours before the surface starts to show micro-scratches that transfer to your resin. To extend mould life, avoid using sharp tools inside the mould, demould gently (flex the sides rather than pulling), and store flat rather than stacked. Cleaning with isopropyl alcohol after each use keeps the surface in good condition.
Is a resin coaster set a good product for Diwali gifting?
It is one of the best. Resin coasters are practical, visually striking, and feel handcrafted β which is exactly what people want for Diwali gifts. A set in deep jewel tones (burgundy, emerald, navy) with gold pigment swirls photographs beautifully and aligns with the festive aesthetic. Packaging in a fabric-covered box with a small tag explaining the handmade process adds perceived value. Many home-based resin sellers in India report their highest monthly sales in October-November specifically because of Diwali gifting demand.
Do I need to seal or coat the finished coasters?
If you used a good quality epoxy resin and cured it fully (72 hours), the surface is already hard and water-resistant. You do not need an additional sealer for functional coasters. However, if you sanded the edges or the top surface to remove imperfections, those sanded areas will be matte. You can restore the gloss by applying a very thin coat of fresh resin over the sanded area, or by buffing with a resin-specific polishing compound. Avoid recommending your buyers put them in a dishwasher β the heat and detergent will eventually dull the surface.
Wrapping Up
A mixed-size resin coaster set round moulds combination β specifically 4", 6", and 8" β is one of the smartest product formats you can work with as a resin artist. It photographs well, gifts well, and gives buyers something they cannot find in a regular home goods store.
The process is straightforward once you understand the basics: prepare your moulds, mix your resin correctly, pour largest-to-smallest, cure properly, and finish with care. The design possibilities are almost unlimited β every season, every colour trend, every gifting occasion gives you a reason to create a new variation.
Shrebhavi stocks all the moulds you need to get started, from the compact 4" round to the substantial 8" deep mould β and if you want to add texture to your 6" pieces, the zigzag agate mould is worth trying. Start with one set, photograph it well, and let the process teach you the rest.