An acrylic sheet order is one of the few plastic purchases where the process behind the sheet changes how it fabricates. An acrylic sheet supplier sells the same polymer through two routes: cell casting, which pours syrup between glass plates, and continuous extrusion through a flat die. This page explains the difference and what to confirm before an order.
Cast Acrylic Sheet vs Extruded PMMA Sheet
Cell casting builds molecular weight in the sheet itself, so cast acrylic sheet is the stronger material: it machines and polishes cleanly, holds thickness tolerance on thick gauges, and is the preferred blank for displays and signage. Extruded pmma sheet runs continuously, so it wins on thin-gauge availability below 2 mm, gauge consistency and price; the sheet behind most lighted signs is extruded. The practical test: sheet that will be routed, polished or thermoformed belongs in cast; sheet cut flat and mounted runs fine as extruded at lower cost.
Thickness, Sizes and Finishes
- Thickness: extruded from about 1.5 mm to 6 mm; cast from 2 mm to 20 mm routinely, thicker on request.
- Sheet size: 1220x1830 mm and 2030x3050 mm are common stock formats; cut-to-size reduces waste but adds cost.
- Clarity and colour: clear, opal and transparent colours plus opaque colour-match options; clear grades transmit up to about 92%.
- Surface finish: gloss both sides, matte or textured for light diffusion, and brushed or pearlescent decorative finishes.
UV, Outdoor and Indoor Grades
Acrylic is inherently UV-transparent, which makes an unstabilised sheet yellow and craze outdoors. A signage or glazing project should specify a UV-stabilised grade rather than the word "acrylic" alone, and ask which stabiliser package the sheet carries. A weathering result from an accelerated UV test is the evidence. Indoor display and furniture uses can run standard grades, which is where extruded acrylic sheet earns its cost advantage.
Fabrication Behaviour
A sheet purchase buys a fabrication chain: cutting, routing, drilling, bending, bonding and polishing. Cast acrylic polishes to an invisible edge after flame finishing; extruded sheet can show a faint line after edge work and machines best with sharp tooling. Both thermoform well, but cast sheet tolerates deeper draws. Solvent bonding gives joints that read as one piece when edges are prepared square. Buyers sending sheet to a fabricator should pass the grade and process with the order.
What to Confirm With an Acrylic Sheet Supplier
Before an order, pin the process (cast or extruded), the gauge and its tolerance, the sheet size and cutting, the UV grade for the intended service, and the protective masking; both faces should carry a handled film that peels without residue. Importers should also confirm REACH and RoHS statements for EU destinations and the customs code in the HS 3920 or 3926 family. The plastic materials category lists other sheet supply; the HS code guide for plastic exports covers customs, the EU and US plastics compliance map explains declarations, and the China plastics company directory lists verified suppliers.
Related product categories
The materials and part types discussed above are grouped in our sourcing directory:
