Dianne asked about seam allowances. This is a good question. After studying the pictures uploaded by Dot, the lady who organized the first swap, I just realized that some of the squares are small collages made on different materiales (like aquarell paper, wallpapers, etc.)
Some others are stitcheries with the edges open -no seam allowances- (you can see that, and I think that there are not so many textile pieces after all!)
So the answer to this question is "no seam allowances"! this lets the piece look more textile and throuws interesting shadows on the background. The piece is 1"x1" (2,5cmx2,5cm) without counting the loose threads of the edge!
This raises a question which I'm going to answer in the next post (please, read the mail above this one!).