The linen tester is – one suspects it – an optical device used initially in the textile industry: for counting the threads in fabrics. Usually, and this is also the case here, you can fold the tester flat for carrying it with you when you are on the move. Nowadays, graphic designers and printers use the linen tester to evaluate the quality or resolution of prints, materials testers of any industry use the device as well. Our linen tester comes from Schweizer Optik. Founded in 1840 in the Bavarian town of Forchheim as a glass grinding shop, the company still specializes in the production of technician magnifiers and reading aids. The Bavarians opt for solid brass for their linen tester and have it matt chrome-plated. As declared friends of visible material surfaces, we asked the manufacturer to dispense with the final chrome plating and to produce a small edition of linen testers with bodies made of raw, uncoated brass exclusively for us. The result is a remarkable magnifying instrument with a no less impressive patinating surface. Our product photos show the device after a short period of use and give an impression of how the surface develops character.