Choosing the right concrete and eco resin sealer is the last decision in making a cast piece production-ready, and it is the one most beginners skip or get wrong. The finish you apply after cure does three jobs: it closes the micro-pores in the surface to protect against moisture and staining, it determines the final visual quality of the piece, and it is often the difference between something that looks handmade and something that looks intentionally crafted.
I'm Anirudh, founder of Artriso. This guide covers sealing for CALSO ONE eco resin and decorative concrete, with specific recommendations for each of the three finishes we supply: Stone Wax, GlazeSeal, and Liquid Glass Varnish. The right choice depends on the piece and what the customer is paying for. If you want the full picture on why eco resin needs sealing at all, the waterproofing guide covers the material science directly.
Do you always need to seal?
For functional pieces: yes. Coasters, trays, planters, and candle jars all contact moisture. An unsealed CALSO ONE coaster will absorb water ring impressions and dull with use within a few weeks of daily handling. Sealing is not optional for anything you intend to sell or use for its intended purpose.
For purely decorative display objects with no water contact, sealing is optional. An unsealed matte eco resin piece has a raw, mineral character that some studio aesthetics lean into. But even for decorative pieces, sealing provides scratch resistance and dust-repellent properties that preserve the surface over time.
For concrete pieces: always seal. Concrete is more porous than eco resin and will stain from oils, liquids, and ambient dust without a sealed surface.
Choosing the finish before you seal
The single most common sealing mistake is reaching for a product before thinking about the final appearance you want. The three finish types are different enough that applying the wrong one cannot be undone without stripping or re-sanding. Think about the finish before you pour, not after.
Natural satin: Stone Wax. Stone Wax is a handcrafted blend of Carnauba wax, beeswax, and orange oil. It buffs to a soft satin sheen that reads as natural stone rather than coated craft. No high-gloss artificial look. The finish deepens colour slightly and preserves the matte mineral character of the raw cast. It creates a water-resistant barrier and leaves the surface smooth to the touch. Stone Wax is the right sealer for sculptural objects, minimal earthy aesthetics, and any piece where the brief is "this should look like it came from a material, not a factory". Apply with a soft cloth, buff in small circles, and allow 15 to 20 minutes before the piece is ready to handle.
High-gloss ceramic look: GlazeSeal. GlazeSeal is a water-based acrylic sealer that cures to a hard, glass-like finish. It deepens pigment saturation, increases the contrast in terrazzo and marble swirl patterns, and gives the piece a polished ceramic appearance. It is scratch-resistant, water-resistant, and stain-resistant. Two coats is the standard for coasters and trays. Three coats for planters and pieces with direct water exposure. GlazeSeal is the right sealer for any piece where the customer is paying for a premium finish: gifting sets, homewares, retail products, and anything where the sealed version should look categorically more valuable than the unsealed version. Apply with a soft brush or use the dip method for smaller pieces.
Ultra-gloss wet-look: Liquid Glass Varnish. Liquid Glass Varnish delivers a deeper, "wet mirror" finish that goes further than standard high-gloss. The cured surface has a depth that reads like the piece is still slightly wet. It also functions as a metallic medium: mixed with mica powder, it creates a flowing metallic paint for edge details and accents. Apply in thin coats with a soft brush. It can be diluted up to 10 percent with water for smoother application on detailed surfaces. Liquid Glass is the right choice for pieces where maximum visual impact matters: statement centrepieces, custom commissions, and any eco resin work that needs to hold its own in a retail or exhibition context.
If you are still working out which finish suits your range, the Ultimate Sealer Kit includes all three. It is the practical way to test each finish on sample pieces before committing to a production run.
Sealing protocol
The steps are the same regardless of which sealer you use.
Wait for full cure first. CALSO ONE reaches full mechanical strength at 24 hours. Sealing before 24 hours can trap residual moisture in the cast and compromise the bond between the sealer and the substrate. Do not seal at demould time just because the piece feels hard.
Sand if needed, before sealing. If the surface has any rough edges, tool marks, or casting imperfections, sand them out with 220-grit sandpaper and wipe clean with a dry cloth before applying sealer. Never sand after sealing.
Apply in thin, even coats. For brush-applied sealers, use smooth, even strokes in one direction. Avoid going back over an area you have already coated while it is still wet. Thick application causes streaks and uneven sheen. Thin and even is always better.
Allow full dry time between coats. For GlazeSeal and Liquid Glass, allow at least 30 to 60 minutes between coats in normal Indian indoor conditions. In high humidity above 70 percent, extend this to 90 minutes to allow full surface drying. Applying a second coat over a tacky first coat will lift the first coat and create a cloudy, uneven result.
Cure before use. After the final coat, allow the sealed piece to cure for 24 hours before use. The surface may feel dry to the touch after an hour, but the sealer continues to harden and achieve its full protective properties over the full cure window.
Sealing concrete vs eco resin
The protocol above applies to both materials, but concrete requires one additional consideration. Decorative concrete has a higher porosity than CALSO ONE eco resin, which means the first coat of any sealer will absorb more heavily and may look uneven. A light sanding between the first and second coat levels the surface before the finishing coats go on. For eco resin, this intermediate sanding step is typically not necessary unless the first coat reveals a specific surface issue.
For planters made from concrete, a penetrating sealer applied inside the cavity before the decorative top coat provides an additional barrier. This is not required for eco resin planters sealed with GlazeSeal, as the acrylic film forms a complete surface barrier.
Common sealing mistakes
The mistakes we see most from studio makers and workshop students:
Sealing before full cure. This is the most common cause of sealer failure. The piece demoulds looking good, the maker seals immediately, and the sealer does not bond properly. Always wait 24 hours.
Using the wrong sealer for the finish. Stone Wax over a piece that was supposed to be high-gloss reads as unfinished. GlazeSeal over a piece that was supposed to be natural-looking reads as over-processed. Decide on the finish before the pour, not after.
Applying too thickly. One heavy coat does not equal two thin coats. A thick single coat will dry unevenly, pool at edges, and may crack over time. Two or three thin coats, fully dried between applications, always outperform one heavy coat.
Not buffing Stone Wax to completion. Stone Wax requires buffing with a dry cloth to activate the satin sheen. Applying it and walking away produces a surface that looks slightly cloudy or oily rather than satin. A 60-second buff per piece is all it takes.
The complete eco resin guide covers the full material context for CALSO ONE, including how the mineral-acrylic chemistry affects surface behaviour and absorption.
Frequently asked questions
Which Artriso sealer is best for coasters?
For coasters that will see daily use with wet glasses, GlazeSeal is the right choice. Its acrylic film creates a hard, water-resistant barrier that handles repeated moisture contact. Two coats applied after full 24-hour cure is the standard. If your aesthetic calls for a natural stone look, Stone Wax also provides a water-resistant barrier and is appropriate for coasters that will see moderate rather than constant moisture contact.
Can I use Stone Wax on planters?
Stone Wax creates a water-resistant barrier but it is not as impermeable as an acrylic sealer for pieces that hold water continuously. For planters that will be watered regularly, three coats of GlazeSeal inside the planter cavity is the recommended approach. Stone Wax is more suitable for the exterior decorative surface of a planter where it will not contact pooled water directly.
How is Liquid Glass different from GlazeSeal?
Both are high-gloss acrylic-based sealers, but Liquid Glass delivers a deeper, "wet-look" mirror finish that goes significantly further in gloss level than GlazeSeal. Liquid Glass also doubles as a metallic medium when mixed with mica powder, making it a dual-purpose product for studios that work with metallic effects. GlazeSeal is the standard production sealer for most coasters, trays, and gifting pieces. Liquid Glass is the step up for statement pieces and maximum visual impact.
Do I need to sand between sealer coats?
Not for standard multi-coat application. Apply thin, even coats with full drying time between each and sanding is not necessary. If the first coat reveals surface imperfections or has a rough texture, a very light sand with 400-grit paper followed by a clean wipe prepares the surface for the second coat. This is more common with concrete than with eco resin.
Anirudh Rapole is the founder of Artriso, the Hyderabad studio behind CALSO ONE. Sealing questions? Email contact@artriso.com.
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