If you have an A3 sized frame that you want to to put an A4 sheet / artwork / photograph / certificate into, this is the solution you've been looking for !
Kenro are the UK's largest & leading supplier of quality frames for art, photography and certificates - and their mounts are exceptionally good too
This is a single Kenro A3 size quality white card mount with a bevelled A4 aperture - for artwork, photography or certificates in A4 size
We have many dozens of these available - please message us to request pricing for a bulk purchase