Independent comparisons. We may earn from shop links. More info

Polycarbonate vs acrylic

Updated: 23 October 2026

You have two tabs open, one titled Perspex and one titled polycarbonate. They are not the same plastic. Polycarbonate vs acrylic is a choice about knocks, scratches, and whether the sheet lives outdoors. Choose acrylic for a clearer, harder surface on a small sheltered shed window. Choose polycarbonate when the sheet might be hit, or when it is a greenhouse skin that must not crack as you fit it. The multiples below are Plastics Direct's comparison, not a test of any listing in our [polycarbonate sheet comparison](/hub/diy-supplies/polycarbonate-sheet). Acrylic packs were removed from the table. A qualifying purchase can earn a commission at no extra cost to you.

You have two tabs open, one titled Perspex and one titled polycarbonate. They are not the same plastic. Polycarbonate vs acrylic is a choice about knocks, scratches, and whether the sheet lives outdoors.

Our top picks

Panda Ant Panda Ant 4 mm solid sheet

Best overall

Panda Ant Panda Ant 4 mm solid sheet
7.6/10about £24.99
View offer
CHEOAR CHEOAR 4 mm twin-wall 10-pack

Best value

CHEOAR CHEOAR 4 mm twin-wall 10-pack
7.4/10about £61.99
View offer
SANJIAOJIA SANJIAOJIA sheet, 1 m × 2 m

Alternative

SANJIAOJIA SANJIAOJIA sheet, 1 m × 2 m
5.5/10about £32.90
View offer
On this page
  1. 1.Two plastics, not one
  2. 2.Impact, clarity, and scratches
  3. 3.Shed window or greenhouse roof
  4. 4.What that means for the sheets we compared

Two plastics, not one

Acrylic is polymethyl methacrylate. In the UK it is sold as Perspex, and Plexiglass is another trade name for the same family. Polycarbonate is a different polymer: softer at the surface, much harder to shatter, and it needs a UV layer if it lives in the sun. Fibreglass rolls are a third mistake, and they were taken out of this comparison with the acrylic packs. None of the four listings we kept is acrylic. The solid Panda Ant pane has polycarbonate in the material field, and the manufacturer field reads Exolon. The thin SANJIAOJIA sheets also name polycarbonate. The CHEOAR twin-wall pack is less helpful: the material field only says Plastic. Plastic is not a specification. Read the bullet that names the polymer before you pay.

Impact, clarity, and scratches

Plastics Direct's comparison, which is their table and not our measurement, puts acrylic at about ten times the impact resistance of glass and about 92% light transmission. They put polycarbonate at about 250 times glass and about 88% light, easier to scratch, and in need of a UV layer outdoors. Do not treat 250 times as a test of the £24.99 pane. Minitec says polycarbonate dents and scratches while acrylic stays shiny and can crack. Catch the edge while you fasten a greenhouse bar, and acrylic is the one that splits. Plastics Direct describes acrylic as naturally more UV-stable than uncoated polycarbonate. Other sellers warn that untreated acrylic yellows. Uncoated polycarbonate hazes if the UV face is missing or fitted inside.
Panda Ant Panda Ant 4 mm solid sheet

Testsieger

Panda Ant Panda Ant 4 mm solid sheet
7.6/10about £24.99
View offer

Shed window or greenhouse roof

For a small shed window in a sheltered wall, acrylic is the usual clearer pane. You get the harder surface, and the impact risk is low. A polycarbonate shed window is the better call if the shed faces a path or a gate that swings. That advice does not travel to a greenhouse roof. The RHS notes that twin-walled acrylic transmits about 85% of light and is more brittle than polycarbonate, with a tendency to crack during fitting. Use polycarbonate for the greenhouse roof and sides. The 4 mm and 6 mm choice is on our polycarbonate sheets for a greenhouse page. A picture frame indoors can go acrylic. A cold-frame lid, which gets knelt on and dropped, goes polycarbonate.

What that means for the sheets we compared

Once you have chosen polycarbonate, the thickness is a separate decision. The polycarbonate sheet buying guide holds 4 mm, 6 mm, 10 mm, and the fact that this set stops at 4 mm. We removed acrylic, canopy kits, and fibreglass so the comparison would not rank a Perspex offcut against a greenhouse pack. If you want acrylic for the sheltered shed window, buy it as acrylic, from a seller who states Perspex or cast acrylic. Acrylic cracks at a rushed edge. End tapes and a UV face belong to polycarbonate multiwall, not to a solid acrylic window.

Common questions

Are Perspex and polycarbonate the same?
No. Perspex and Plexiglass are trade names for acrylic. Polycarbonate is a different polymer: tougher against impact, easier to scratch, and dependent on a UV face outdoors. A title that says clear sheet can be either. Read the material line. If it only says Plastic, the listing has not told you which one you are buying.
Which is stronger?
On Plastics Direct's figures, polycarbonate is about 250 times as impact resistant as glass, and acrylic about 10 times. Those are their numbers, not a test of the sheets in our table. Polycarbonate is the one that survives a knock. Acrylic can crack while you are still fitting it, which is also what the RHS says about acrylic twin-wall.
Which is clearer and more scratch resistant?
Acrylic, on the same trade comparison: about 92% light transmission against about 88% for polycarbonate, with a harder surface that stays shiny. Polycarbonate marks if a fitting drags across it. The RHS puts clear polycarbonate nearer 83% against glass at about 90%, so do not mix that garden figure with Plastics Direct's 88% and call them one measurement.
Which should I put in a shed window?
For a small window on a sheltered wall, acrylic is the usual choice: clearer, harder, and enough for a low-impact opening. Choose the solid polycarbonate pane if the window is large, low, or likely to be hit. The 610 mm by 457 mm sheet in our set is the polycarbonate version of that single pane, not an acrylic sheet with a different name.
Which belongs on a greenhouse roof?
Polycarbonate. The RHS finds acrylic twin-wall more brittle and more likely to crack during fitting, even though it can transmit about 85% of light. A greenhouse roof is the knock and the fixing risk, so the shed-window preference for acrylic does not apply. Use 4 mm or 6 mm polycarbonate twin-wall, and do not glaze that roof with a 1 mm roll.
Will acrylic yellow outside?
It might, and uncoated polycarbonate is the more certain fade if the UV face is missing. Plastics Direct treats acrylic as naturally more UV-stable than uncoated polycarbonate. Other sellers still warn that untreated acrylic yellows. Buy a polycarbonate sheet with a printed UV face for a roof.
Why were acrylic packs excluded from the comparison?
Because an amazon.co.uk search for polycarbonate sheet is full of acrylic, fibreglass, and canopy kits. Ranking those against a 4 mm glazing sheet would mix polymers and jobs. The table keeps polycarbonate listings only. If your job is a sheltered shed window, buy acrylic on purpose. If your job is a greenhouse pane, stay with the polycarbonate packs this comparison actually holds.

Related pages

Best polycarbonate sheet

Acrylic glass pane comparison

Polycarbonate sheet

Polycarbonate sheet buying guide for span and type

Polycarbonate sheets for a greenhouse: 4 mm or 6 mm

How to fit polycarbonate sheet without standing on it

Sources

Public UK sources and the amazon.co.uk listings compared on this page. Listings captured 19 October 2026. Updated 23 October 2026.

  1. The Glazing Shop thickness guide (retrieved 19 October 2026)
  2. The Glazing Shop buyers guide (retrieved 19 October 2026)
  3. BSI, BS EN 16153:2013+A1:2015 (retrieved 19 October 2026)
  4. Approved Document B amendments (retrieved 19 October 2026)
  5. Brett Martin TB413 (retrieved 19 October 2026)
  6. Brett Martin Marlon ST (retrieved 19 October 2026)
  7. RHS: choosing greenhouses (retrieved 19 October 2026)
  8. Class E, GPDO 2015 (retrieved 19 October 2026)
  9. The Polycarbonate Store twin-wall (retrieved 19 October 2026)