Linen Testers are strong magnifiers with a measuring scale. Historically they were (and still are) used to check the thread size and the number of woven threads per square inch. They are also used extensive in the graphic designing, desktop publishing, film and plate, photo negatives and agriculture professions.
The purpose of using a Linen Tester is to inspect quality, check fine measurements and colour separations in graphics, measure small details and view of postage stamps, coins, examine prints or negatives.
High quality, 6X magnification, 30 mm single lens, scale plate in metric and imperial measurements.