Don Briel and Fellow Insulator Collectors,

Before the new price guide is finalized, I'd like to suggest once again that the "PRISM" embossing be ELIMINATED from the price guide. It DOES NOT EXIST. At some point in time, someone used this word inappropriately.

As seen in the photo, KNOWLES Trademarked this embossing as an "EMERALD" on February 25, 1902. This Trademark by the manufacturer should be the only evidence needed to make this change. Particularly in a hobby that values historical accuracy and research.

Perform a Google search to see what a prism is and what they look like. A prism is "a solid geometric figure whose two end faces are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms." What we have been calling a "PRISM" simply IS NOT a "PRISM".

Perform a Google search for "EMERALD". You'll quickly see the term "EMERALD" refers to a type of stone and a shape of cut for stones. Not coincidentally, that shape is the same shape that KNOWLES uses and Trademarked as their "EMERALD".

KNOWLES also uses the term "EMERALD GLASS" along with this image in many of their other publications.

I believe the argument for this change is pretty black and white.

Spencer Garten - Temporary caretaker of some EMERALD embossed insulators.