--- product_id: 1871175 title: "Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit" brand: "smooth-on" price: "$84.85" currency: USD in_stock: true reviews_count: 13 category: "Smooth On" url: https://www.desertcart.us/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint store_origin: US region: United States of America --- # Bright white, ultra-low viscosity Shore 70D hardness, machinable 3-min pot life, 10-min cure Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit **Brand:** smooth-on **Price:** $84.85 **Availability:** ✅ In Stock ## Summary > ⚡ Cast fast, shine bright, and craft like a pro! ## Quick Answers - **What is this?** Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit by smooth-on - **How much does it cost?** $84.85 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint) ## Best For - smooth-on enthusiasts ## Why This Product - Trusted smooth-on brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Durable & Machinable:** Rigid Shore 70D hardness lets you drill, sand, carve, and paint your masterpieces with ease. - • **Effortless 1:1 Mixing:** Simple equal-part mixing means no special tools—just pure creative freedom. - • **Bubble-Free Brilliance:** Ultra-low viscosity formula naturally releases trapped air, delivering smooth, professional-grade finishes without vacuum degassing. - • **Lightning-Fast Casting:** Get flawless results in just 10 minutes—perfect for rapid prototyping and production runs. - • **Versatile Compatibility:** Works seamlessly with most silicone molds and materials like glass, metal, and wood for limitless creative possibilities. ## Overview Smooth-Cast 300 is a bright white, ultra-low viscosity two-part polyurethane resin designed for fast, bubble-free castings with a 3-minute pot life and 10-minute cure time. It cures to a durable Shore 70D hardness, allowing machining and painting, and mixes easily in a 1:1 ratio without vacuum degassing. Ideal for professionals and hobbyists seeking high-detail, rapid production in molding, prototyping, cosplay, and special effects. ## Description Smooth Cast 300 is a liquid plastic ,ultra-low viscosity casting resin that yields castings that are bright white and virtually bubble-free. Vacuum degassing is not necessary. It offers the convenience of a one to one mix ratio (by volume). 3 minute pot life: 10 minute demold time: Mixed viscosity 80 cps: 70D shore hardness Fully cured castings are tough, durable, machinable and paintable. Read MSDS before use - Adult Supervision Required. Keep Out of the Reach of Children - for more information visit www.smooth-on.com Review: Well I suppose it is easy to use (with experience), I do not quite know what is "sheerness" means. - Well I do not know what "sheerness" means except perhaps get a better writer. It is strong and for me easy to use. Of course I mostly use injecting into molds (Larger hypodermic syringes') but one can pore it as well. I have used Smooth Cast for about 10 years now and I have not seen another product that is it's match. I also use dye to change the color, mostly black. I also like the fast cure time (10 min). The plastic can handle negative curves in complex molds. I also like the cleanup as simple alcohol cleans out the the syringes and injector tubes. Great product. Now if someone will explain to me what "sheerness" means? Review: Great stuff! - I like that this cures really fast. Worked great for my mask project. ## Features - FAST-CURING BRIGHT WHITE CASTING RESIN – Smooth-Cast 300 is an ultra-low viscosity, two-part liquid polyurethane plastic that produces bright white castings with excellent detail. Its free-flowing formula fills intricate molds with ease for professional-quality results. - VIRTUALLY BUBBLE-FREE CASTINGS – The ultra-low viscosity formula allows trapped air to escape naturally, eliminating the need for vacuum degassing in most applications. Create smooth, high-quality castings with minimal bubbles and outstanding surface finish. - RAPID SET & DEMOLD TIMES – Designed for high productivity with a 3-minute pot life and 10-minute cure time, allowing you to make multiple castings in a short period. Ideal for prototyping, production runs, cosplay props, model making, and special effects. - STRONG, RIGID & MACHINABLE – Cures to a durable Shore 70D hardness, producing rigid castings that can be drilled, sanded, carved, machined, and painted. The bright white finish also provides an excellent base for custom colors and decorative finishes. - EASY 1:1 MIXING FOR PROFESSIONAL RESULTS – Mix equal parts of Part A and Part B by volume—no specialized equipment required. Compatible with most silicone rubber molds and trusted by artists, designers, manufacturers, prop makers, and hobbyists for detailed, reliable castings every time. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B004BN7G0E | | Best Sellers Rank | #12,723 in Arts, Crafts & Sewing ( See Top 100 in Arts, Crafts & Sewing ) #123 in Sculpture Molding & Casting Products | | Brand | Smooth-On | | Brand Name | Smooth-On | | Compatible Material | Glass, Metal, Plastic, Stone, Wood | | Customer Reviews | 4.7 out of 5 stars 1,319 Reviews | | Grit Material | Plastic | | Grit Material Type | Plastic | | Grit Number | 300 | | Grit Type | Fine | | Item Dimensions | 7.4 x 6 x 3.1 inches | | Item Type Name | Casting Resin | | Item Weight | 2 pounds | | Item dimensions L x W x H | 7.4 x 6 x 3.1 inches | | Manufacturer | Smooth-On, Inc. | | Material | Plastic | | Material Type | Plastic | | Model | 47641 | | Number of Items | 1 | | Part Number | 47641 | | UPC | 751635476417 | | Unit Count | 1 Count | ## Product Details - **Brand:** Smooth-On - **Grit Material:** Plastic - **Grit Type:** Fine - **Item dimensions L x W x H:** 7.4 x 6 x 3.1 inches - **Material:** Plastic ## Images ![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 1](https://m.media-amazon.com/images/I/81gwmekNnqL.jpg) ![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 2](https://m.media-amazon.com/images/I/71ZWTS1-Q2L.jpg) ![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 3](https://m.media-amazon.com/images/I/81ubKEjBDDL.jpg) ![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 4](https://m.media-amazon.com/images/I/71Koo4ru1vL.jpg) ![Smooth-Cast 300, Bright White, Ultra Low Viscosity Liquid, Pint Unit - Image 5](https://m.media-amazon.com/images/I/71LJ0Lk-VZL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Can I add glitter to this?** A: I've used 325 with glitter pigments, and it works very well. You'll have to add a decent amount of glitter and it will take longer to cure. **Q: Can I use this to cast a dome-shaped mask using a silicone mold? Will it stay liquid long enough for me to tilt it back & forth to form an even coat?** A: Smooth-Cast 300 is a snap cure material - a better choice may be Smooth-Cast 325 or Smooth-Cast 65D, both of which have a gradual cure profile. **Q: is it machinable?** A: Yeah, to an extent. I’ve taken a dremle tool to casted plastic to sand down parts and remove unwanted flashing that occurs. It’s pretty tough stuff, let it cure for a day or two before sanding or working on thinner areas, but I’ve even taken a hacksaw to some castings and they have held up just fine. **Q: Is this a silicone or a urethane?** A: This is a urethane casting resin. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Well I suppose it is easy to use (with experience), I do not quite know what is "sheerness" means. *by N***X on December 16, 2023* Well I do not know what "sheerness" means except perhaps get a better writer. It is strong and for me easy to use. Of course I mostly use injecting into molds (Larger hypodermic syringes') but one can pore it as well. I have used Smooth Cast for about 10 years now and I have not seen another product that is it's match. I also use dye to change the color, mostly black. I also like the fast cure time (10 min). The plastic can handle negative curves in complex molds. I also like the cleanup as simple alcohol cleans out the the syringes and injector tubes. Great product. Now if someone will explain to me what "sheerness" means? ### ⭐⭐⭐⭐⭐ Great stuff! *by M***E on December 13, 2025* I like that this cures really fast. Worked great for my mask project. ### ⭐⭐⭐⭐⭐ Works Amazing. Used for Complex Thin Walled Two-Part Mold. Just Don't Add Filler/Color or Degas *by B***N on December 18, 2024* Worked perfectly for my needs. Very little bubbling even when pouring it directly into a two-part thin walled cast squish mold with very little venting built into the mold. Even though my casted part is probably 1/8 of an inch thick at its thickest point, and probably half that at it's thinnest, this product is still very durable. Surprisingly. I was expecting I may needed to get the Smooth Cast Task series product over the Smooth Cast 300 to get what I needed for such a thin cast. First attempt at a cast I tried degassing the mixed resin. Spent one minute mixing. And one minute or so degassing. Which should have left me with one final minute of potlife. Nope, within a 3 second period between having my eyes on the resin in the chamber, I look back and see a very hot eruption of resin that instant cured into a soft foam in the shape of magma pouring out of the cup like a volcano lol. Lesson #1 learned. No degassing. First cast I used release (really just cooking spray) and black pigment powder. And it came out horrible. Finish was rough and textured, and the color was grey although I used a ton of black pigment. And ultimately it made the cast extremely brittle and it broke in two places while sanding/trimming. Lesson #2 learned. No additives, and avoid release agents (or at least particularly non-cast specific release agents). Without any additives or any release (still released perfectly fine without any chemical release) it came out very smooth and very durable. It also sands amazingly well. Doesn't clog up sanding paper, sands down powdery and easily. Also the cast was a motorcycle helmet spoiler that isn't sold separately anywhere. Was a very expensive handmade Portuguese carbon fiber racing helmet. I decided to learn about molding and casting and made myself a new one using a spoiler to the same model I bought for my girlfriend as a gift. Think of, two birds one stone lol. Gift + master for my own spoiler. For my very first cast, being so complex as it was, and being such an amazing success.. I am completely happy with myself and the results of the various products I've used. Will say though, silicone mold making is definitely much more difficult than the resin casting process haha. Especially two part molds making with non-flat masters. ## Frequently Bought Together - Smooth-Cast™ 300: Bright White, Low Viscosity, Liquid Plastic Casting Resin - Pint Unit - Smooth-On Mold Star™ 16 Fast Platinum Silicone Rubber, Silicone Mold Making Kit - Pint Unit - Smooth-On Universal Mold Release - 14 Fluid Ounce Aerosol Can --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.us/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint](https://www.desertcart.us/products/1871175-smooth-cast-300-bright-white-ultra-low-viscosity-liquid-pint) --- *Product available on Desertcart United States of America* *Store origin: US* *Last updated: 2026-07-25*