Triad Aluminum Slip-In Stereo Slide Masks
Box of 100 - 5 Perf. Regular
Manufactured by one of the two most successful stereo projector manufacturers, both located in Chicago, Illinois, the Compco Corp. It seemed perfectly natural that Comco would gladly develop a unique concept in stereo slide mounts - the patented three piece, laminated slip-in stereo slide mount.
A slightly sturdier aluminum mask than the competition, the Triad masks feature slots for the slip-in of the stereo images, making it the fastest and easiest to align and assemble. They even have a cut-out arrow that directed the user to immediately see what is 'up'.
Once images are installed mask is ready to be sandwiched in glass of cardboard fold-over for increased sturdiness and protection.
Remember that aluminum masks and mounts have always been the preferred method for precision, accurate stereo mounting. And these manufacturers offered different sized and separated windows in their masks.
Triad offered three styles:
REGULAR - for images with near subject 7' away or greater
MEDIUM - for images with near subject between 4' and 7'
CLOSE-UP - for images with near subject closer than 4'
This offering of 100 masks are REGULAR - for images with near subject 7' away or greater.