In our studio, we use sheet solder. It is easy to cut up small
squares to sell to students, and a stamp is made on each square with
a letter stamp. E for easy, M for medium, and H for hard. Very
difficult to mix up. Unlike wire solder which forms a small wheel
when cut, the sheet solder forms a very small flat square, and stays
where you put it. Cutting “fringe” on a piece of sheet solder, I can
cut extremely tiny bits off the fringed ends, which are needed in
many tiny solder repairs or soldering work.
Wire solder also has issue with identification. A “code” is required
for bends in the end of the wire ( what bend is hard solder again?)
and labels can slip off.
Wire solder is improved by running a length of it through the mill
to flatten it, but then you have sheet solder, right?