Hey guys,
Stanley dry plates get their name from the twin brothers F. E. and F. O. Stanley who invented their own dry plate and went into the dry plate business in 1884. Their sister Chansonetta was apparently an accomplished photographer. They sold the plate formula to Eastman Kodak in 1904 (according to the Stanley Museum) and focused on their steam automobile. Kodak later sold the formula to Defender, now Dupont, and the plates were allegedly produced until about 1960.
Anyway, I dug out a 1913 photo supply catalog and it lists Stanley "Regular and Commercial" plates in the following sizes:
2 1/2 x 2 1/2
3 1/4 x 3 1/4
3 1/2 x 1 1/2
3 1/4 x 4 1/4
4 x 5
4 1/4 x 4 1/4
4 1/4 x 5 1/2
4 1/4 x 6 1/2
5 x 7
5 x 8
6 1/2 x 8 1/2
8 x 10
10 x 12
11 x 14
14 x 17
16 x 20
17 x 20
18 x 22
20 x 24
For the record, many Stanley boxes show up, but Seed's, Hammer's, and Cramer's seem to have been listed in more early catalogs.