Sturdy and portable, these slim archival boxes are acid-free and beautifully made. Available in three sizes: A5, A4 and A3. They are lined and bound in charcoal wibalin for durability and a professional finish, so that you can present your work in style. These top quality, slim-line boxes are available at Cass Art at the fraction of conventional prices. Krystal Seal Sleeves are a big hit in the USA and are a perfect accompaniment to the storage boxes.