What Is Just Cast Acrylic?
Just Cast Acrylic is a high-clarity cast acrylic sheet manufactured through the cell-cast process, producing a material with superior optical clarity, consistent thickness, and excellent chemical resistance compared to extruded alternatives. Available in four finish categories — Clear, Diffuser White, Colors, and Mirror — it covers the full range of commercial signage, lightbox, and display fabrication requirements.
Thickness options run from 1.5mm to 12.0mm, and sheets are available in standard 4×6ft and 4×8ft sizes. Just Cast Acrylic is thermoformable, UV stable for outdoor use, and machinable with standard woodworking tools, router bits, and laser cutters.
Just Cast Acrylic Grades & Finishes
| Grade | Light Transmission | Typical Use |
|---|---|---|
| Clear | ~92% | Display cases, protective shields, aquariums, windows |
| Diffuser White | Varies by thickness | LED lightbox faces, channel letter faces, backlit signs |
| Colors | Varies by color | Decorative signage, POP displays, colored panels |
| Mirror | N/A (reflective) | Décor panels, retail displays, wayfinding accents |
Cast vs. Extruded Acrylic: Cast acrylic has superior optical clarity, better chemical resistance, and more consistent thickness. It is the preferred choice for high-quality signage and display fabrication. Extruded acrylic (see Luminao guide) is more cost-effective for budget applications.
Technical Specifications
| Specification | Value |
|---|---|
| Thickness Options | 1.5mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, 8.0mm, 10.0mm, 12.0mm |
| Sheet Sizes | 4×6ft (1220×1830mm), 4×8ft (1220×2440mm) |
| Manufacturing Method | Cell Cast |
| UV Stability | Outdoor rated, UV stabilized |
| Heat Deflection | ~95°C (thermoformable) |
| Density | 1.19 g/cm³ |
| Machining | Laser cuttable, router cuttable, drill compatible |
Common Applications
- Channel Letter Faces: Diffuser White is the industry standard for illuminated channel letters, providing even light distribution from LED strips.
- LED Lightboxes: Diffuser White panels diffuse light uniformly across backlit signage and menu boards.
- Display Cases & Protective Covers: Clear acrylic is widely used for product displays, countertop covers, and exhibition cases.
- Decorative Signage: Colored and mirror finishes are used for lobby signs, retail POP displays, and architectural features.
- Thermoformed Parts: Cast acrylic can be heat-formed into curved panels, 3D letters, and custom shapes.
Which Grade Should You Stock?
For signage fabricators: Diffuser White 3mm (4×8ft) is the most-used sheet for channel letters and lightbox faces. Clear 3mm and 5mm covers most display case and protective cover work. Stock Mirror for upsell on lobby and feature signage.
For general print shops: starting with Clear and Diffuser White in 3mm covers 80% of customer requests. Add colors and thicker sheets as demand grows.