Shop for Light Diffusing Acrylic sheets. OPTIX® LD, light diffusing acrylic sheet, provides superior diffusion properties, impact resistance, and weatherability allowing for greater sign design flexibility with slim profile channel letters. Custom cuts and cut-to-size pieces. Have machined into fabricated parts. Acrylic comes in many colors. Stocked materials typically ship in 2-5 business days. Can’t find what you need? Get a quote.