Mailer Envelopes/Strong E-Flute Cardboard A4 X 10/Pack - Capacity A4 Book Mailers Expand to Fit 50mm Thick - Large Letter Size at 25mm. (234x334mm)

I have been using these to post out artwork and find they work great. Sturdy and secure with no issues. True A4 size too, would recommend.

very good product!

These are great quality at a great price. I’ve paid more for less in the past but these are in my shopping basket most months. 👍