I just purchased this piece at an antique shop in NC and was wondering if anyone has seen anything like this? My husband made a wooden box for the glass plate.
What that is is a glass plate used in making the screens... in your example it's for running the black ink, the last color to be drawn.
I don't remember all the technical terms but basically that plate would be placed in a frame and light shot through it onto the screen for screen printing,
what was exposed to the light would wash away allowing the black ink through the screens.
As you can read along the top you can see it was even labeled black .. for the color ink to be used.
Attached is a cap that used a screen close to your screen to show the final result... the cap would have had a white layer,
would have ran through a drying process then onto the next color orange layer again goes through a drying process then
the final and darkest color, in this case, black... Always worked from lightest color to darkest color.View attachment 173560
Great way to display this piece.