These picture frame mats are ideal for ACEOs or small photos or art. Matboard is all conservation quality acid and lignin free name brands. Frame up your photos. Makes a great Christmas gift the family will love. Fabric matting is also available for a small additional charge. ACEO Picture Frame Mats 6 Six to Fit 2.5 x 3.5" Photos or Art Miniatures. All mats are sized to cover 1/8" of the edges of your miniature ACEO Artwork. photo or print. The opening size is 2 1/4" X 3 1/4" You can choose either an outside dimension of 4 x 6", 5 x 7" or 8 x 10" to fit a standard frame. These mats are all conservation grade. CUSTOM ORDERS WELCOME!