from sheet approx 0.5 thick. The frames are about 4 cms outside
and 3.5 cms inside (so the edges of the frames are 0.5).
Just a little less than clear. I think what you want is to use sheet
0.500 mm thick. You want to cut out squares of 4.0 cm. You want to
cut square holes centered in the 4.0 cm squares of 3.500 cm. This
would leave a frame of 2.500 cm or 25 mm with square corners both
inside and outside. They would be several ways to make these.
Stamping would be expensive for just 50, but you could contact Dar
Skelton. You could make rings from wire and then hammer them into
shape. You could buy strip 25 mm x 0.500 mm thick, cut and solder the
frames. There is a technique that requires some skill that could bend
the 25 mm x 0.500 mm strip into the frame requiring one soldered