Two different squares to help divide a scene for drawing. One feature 15mm squares (2 shown) and is 120mm x 75 mm in internal dimension. The other has 25mm squares and is 125mm x 75mm in internal dimension. For the dividing lines, I used 50# fishing line I got from the local megamart for $2. Modest scale changes should be finew but I did not try this. If scaling down, the frame may become too thin to support the combined force of the dividing lines.