White Opal Acrylic Sheet

Even glow-through white for lightboxes and signage — no hotspots, no visible tube or LED lines.

Opal acrylic is white sheet engineered to glow evenly when lit from behind. The whole skill is in the loading: too little and the LEDs show through as bright stripes, too much and the sign looks grey and dead when switched off.

We supply several opacity grades so the sheet can be matched to your cavity depth and lamp spacing, rather than forcing one grade to work in every fixture.

Specification

Property	Specification
Opacity grades	Multiple, from high-transmission to high-hiding
Light transmission	30–70% depending on grade
Thickness	2 mm – 10 mm
Widths	1220 mm and 1830 mm standard; other widths to order
Colour stability	UV stable — will not yellow in illuminated service
Face options	Gloss both faces, or one face matte
Process options	Cast or extruded

Opal, opalescent, milky white — the same sheet under different names

What the word actually describes is light behaviour, not a separate polymer: opal sheet scatters light through its thickness so an LED or tube behind it reads as an even glow rather than a bright spot. Three things it is regularly confused with:

Frosted acrylic obscures by surface texture, not by scattering through the body. It softens a view; it will not hide a lamp. See frosted acrylic sheet.
White opaque acrylic blocks light rather than transmitting it. If a panel is meant to be lit from behind, opaque white is the wrong specification.
Polycarbonate LED diffuser sheet does the same optical job in a different polymer, with higher impact strength and different fire behaviour. Where the panel is exposed to impact or needs a fire rating, see polycarbonate diffuser sheet.

Choosing the transmission grade

Our opal grades run 30–70% light transmission. Transmission and hiding power move in opposite directions, and the right point on that range is set by the box, not by preference:

Where on the 30–70% range	Hiding power	Typically suits
Higher transmission (towards 70%)	Lower	Deeper cavities and dense LED strips, where the light already has room to mix and brightness matters more than hiding
Mid range	Balanced	The general-purpose signage and luminaire choice when the box is conventional
Lower transmission (towards 30%)	Higher	Shallow boxes and widely spaced lamps, where visible hotspots or lamp lines are the risk being designed out

Brightness lost to a higher-hiding grade can usually be bought back with more or brighter lamps; a hotspot cannot be fixed after the box is built. That asymmetry is why we send samples rather than quote a grade from a description.

Picking the right opacity

Two measurements decide it, and getting them wrong is the most common cause of a rejected sign:

Cavity depth — the gap between lamp and sheet. A shallow lightbox needs a higher-hiding grade because the light has no distance in which to mix.

Lamp spacing — widely spaced LEDs need more hiding power than a dense strip.

Send both figures and we will send samples of two or three grades to test in the actual box before you commit to a production quantity.

Typical applications

Illuminated signage and fascia panels
Lightbox and menu board faces
Luminaire diffusers and covers
Backlit displays and exhibition stands
Illuminated ceilings and wall panels

Questions buyers ask

Is opal acrylic the same as opal plexiglass or opal perspex?

Yes. Plexiglas and Perspex are brand names for PMMA, the same polymer we extrude and cast. Opal acrylic, opalescent acrylic, milky white acrylic and white opal acrylic all describe the same white light-diffusing sheet.

What light transmission does white opal acrylic have?

Our grades run 30 to 70% depending on the opacity chosen. Higher transmission gives a brighter panel with less hiding power; lower transmission hides lamps better and costs brightness. Send the cavity depth and lamp spacing and we will send samples of two or three grades to test in the actual box.

Opal acrylic or polycarbonate diffuser — which should I use?

Acrylic opal is the usual choice for interior signage and luminaires: it is cost-effective and UV stable in illuminated service. Choose polycarbonate diffuser where the panel faces impact, vandalism or a fire-performance requirement, since polycarbonate is far tougher and available in flame-retardant grades.

What is the difference between opal acrylic and white acrylic?

Opal is translucent and designed to be lit from behind. Solid white is opaque and used where light should not pass. Ordering the wrong one is a common and expensive mistake.

Will the white go yellow when lit continuously?

Not in our sheet — PMMA is inherently UV stable. Yellowing in illuminated signage usually comes from cheap recycled base material or from lamps running too hot against the face.

Can you match the opacity of the sheet I currently use?

Yes. Send a sample piece and we will match transmission and colour, then supply a comparison sample before you order.

Request a quote MOQ & shipping

From the factory