400 x 300 mm, Mounts & Backs, Pack of 5 Colour:Black All colours are acid-free white-core

All colours are acid-free white-core mountboard

Outer Size to fit a 11 x 11 inch frame - exact outer size 277mm x 277mm

Outer Size to fit a 20 x 16 inch frame - exact outer size 505mm x 404mm

Outer Size to fit a 12 x 10 inch frame - exact outer size 302mm x 251mm

Outer Size exactly 320mm x 320mm

400 x 300 mm, Mounts & Backs, Pack of 5 Colour:Black All colours are acid-free white-coreOuter Size exactly 400mm x 300mm, 40cm x 30cm Choice of aperture size Scroll through the pictures to find the size that best fits your artwork, then select it from the dropdown menu. Choice of colour On screen colours may not be true to life. Order colour samples here. Select your preferred colour from the dropdown menu. All colours are acid free white core mountboard, 1. 4mm thick.