For instance, 875-11 would indicate the 11th sheet made that day from formula 875. Since the ruby color would continue to strike as it was reheated, the Bryn Athyn craftsmen learned by experimentation to fire the red sheets to a temperature above the point at which the glass would be fired by the glass painters later in the window- making process; otherwise the color would continue to darken. The temperature of the second firing (typically 1180 degrees F) was also inscribed on the sheets. Apparently Saint used the same coding system he had learned at Bryn Athyn as his sheets were identically marked.
We may never know if Saint’s formula is exactly the same as the Bryn Athyn formula, which Ariel Gunther may have taken to his grave, but I feel confident in saying that they must have been very close. At least they appear visually identical.