# Best Casting Slip Source: https://potterynest.com/best/best-casting-slip Updated: 2026-09-14 Publisher: Pottery Nest. Our score is an editorial rating out of 10 (fit 35%, features 25%, build 20%, value 20%), not a customer rating. Method: https://potterynest.com/how-we-research#our-score Casting slip is liquid clay formulated to be poured into plaster molds, where the plaster draws out water and builds an even wall along the mold surface. For home potters, slip casting is the gateway to repeatable forms, letting you produce matching mugs, planters, or figurines that would be slow to throw or build one at a time. Premixed slips save you from the fussy chemistry of deflocculation, and the main decision is the clay body: porcelain slips cast bright white and translucent, stoneware slips are sturdier, and low-fire slips suit hobby kilns and bright glazes. Check the firing range against your kiln, along with specific gravity and how quickly the slip builds wall thickness. These are the slips that cast cleanly. ## Picks ### 1. Penguin Pottery - Darvan 7 - Dispersion Agent - Deflocculant - Sodium Silicate Substitute - Will Not Erode Plaster Molds - 16 oz Our score: 8.4/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 8/10 · Value 8/10) Penguin Pottery's 16 oz Darvan 7 dispersion agent, a sodium silicate substitute that will not erode plaster molds. Pros: - Gentler on plaster molds than sodium silicate, so molds last longer - 16 oz bottle is a practical size for regular slip mixing - Clear labeling as a sodium silicate substitute helps beginners choose Cons: - Still needs careful measuring, since over-deflocculated slip misbehaves - Costs more than basic sodium silicate for the same thinning job Details: https://potterynest.com/product/B08C4TC336 ### 2. AMACO No. 15-S 1 Gallon Casting Slip Our score: 8.1/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) AMACO No. 15-S 1 Gallon casting slip, a ready-to-pour liquid clay for slip casting in plaster molds. Pros: - Ready-to-pour slip saves mixing powder and deflocculant yourself - 1 Gallon container fills several small to medium molds - AMACO slip is widely used in schools and ceramic hobby shops Cons: - Plaster molds are needed and are not included - Slip settles over time and must be stirred well before pouring Details: https://potterynest.com/product/B0044S9G86 ### 3. AMACO No. 1, 1-Gallon Porcelain Slip Our score: 8.1/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) AMACO No. 1 porcelain slip in a 1-Gallon container, a ready-made liquid porcelain for casting fine white pieces in molds. Pros: - Porcelain slip casts thin, bright white pieces with crisp detail - 1-Gallon size fills a good number of cup and ornament molds - Pre-mixed by AMACO, so the slip is consistent from pour to pour Cons: - Porcelain casts need careful drying and gentle handling when greenware - Test fire a small batch to confirm it matches your kiln range Details: https://potterynest.com/product/B008HYRWK2 ### 4. Darvan 811 Deflocculant - Ceramic Additive for Slip Casting & Pottery, 1 Pint, Ceramic Supply USA Our score: 7.8/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Darvan 811 deflocculant in a 1 Pint bottle from Ceramic Supply USA, an additive for mixing fluid, low-water casting slip. Pros: - Darvan 811 thins slip with less water, reducing shrinkage and mold wear - 1 Pint bottle lasts a long time since only small doses are needed - Useful for potters who mix their own casting slip from clay or powder Cons: - Dosing takes testing, and too much can make slip thicken again - Not a slip itself, so you still need clay or dry materials to mix Details: https://potterynest.com/product/B0F2P65WWF ### 5. Darvan 7 Deflocculant - 1 Pint, Premium Ceramic Casting Slip Additive for Pottery & Clay, Ceramic Supply USA Our score: 7.8/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Darvan 7 deflocculant in a 1 Pint bottle, a premium casting slip additive for pottery and clay from Ceramic Supply USA. Pros: - Darvan 7 is a widely used dispersant for stable, pourable slips - Helps keep slip fluid without adding extra water that weakens casts - Works in glazes too, helping heavy materials stay suspended Cons: - Requires small, measured additions and some trial batches - Only useful if you make or adjust slip, not for ready-made users Details: https://potterynest.com/product/B0F3LL5ZFX ### 6. RT Vanderbilt DARVAN 7-N Premium Liquid Slip & Glaze Dispersing Agent - Deflocculant for Stable Ceramic Casting Slips & Glazes Our score: 7.5/10 (Fit for the job 8/10 · Features and specs 6/10 · Build and materials 9/10 · Value 7/10) RT Vanderbilt's DARVAN 7-N premium liquid dispersing agent, a deflocculant for stable ceramic casting slips and glazes. Pros: - Made by RT Vanderbilt, the original manufacturer of the Darvan line - 7-N formula helps slips stay stable over longer storage - Doubles as a glaze dispersant to reduce settling in buckets Cons: - Check the bottle size against how much slip you process - Industrial-style packaging offers little guidance for beginners Details: https://potterynest.com/product/B07X13KL43 ### 7. SOLIDLAND Sodium Silicate Solution for Pottery & Ceramics - 8.5 FL.OZ - Water Glass for Glazing, Slip Casting, Deflocculant - 40% Concentration Our score: 7.2/10 (Fit for the job 7/10 · Features and specs 7/10 · Build and materials 7/10 · Value 8/10) SOLIDLAND's 8.5 FL.OZ sodium silicate solution at 40% concentration, a water glass for slip casting and pottery uses. Pros: - Sodium silicate is a low-cost classic deflocculant for casting slip - 40% concentration is clearly stated, which helps with dosing - Also useful for crackle texture effects on thrown pieces Cons: - Sodium silicate can gradually glaze and seal plaster mold surfaces - Small 8.5 FL.OZ bottle suits testing more than big slip batches Details: https://potterynest.com/product/B0GVPD8SF8 As an Amazon Associate I earn from qualifying purchases.