I'm selling the mat boards that came with an A4 frame, as I won't be using them. These are white, A4-sized mat boards made of thick paper, with an opening of approximately 17cm x 24.6cm, allowing you to display B5-sized artwork, etc., in an A4 frame. There are 5 sheets in a set. I'm not sure of the exact paper type, but it's similar to the paper and thickness used for cake boxes. Although unused, please be aware that they have been stored for a long time. *Initially, I'm selling them as a set of 5, but if you'd like to change the number, please comment. I have a maximum of 26 sheets in stock. - Quantity: Multiple sheets - Color: White - Size: A4 with an opening of approximately 17cm x 24.6cm (Measurements are approximate. Please also check the photos) - Material: Thick paper Thank you for looking.