Original vintage ad for MINNESOTA MINING MANUFACTURING COMPANY.  3M tips on storing magnetic tapes.  Store in the original box to protect against dirt and damage.  Avoid long exposure to extreme temperatures and humidity.  Clean recorder heads and guides periodically following recorder manufacturer's instructions, and avoid excessive winding tension that might stretch or distort tape. Tartan Tapes come in four series, No. 141, 140, 142 and 144.
Main office was located in St. Paul, MN.
This unique old one page 1961 high fidelity stereo equipment trade magazine advertisement would display beautifully matted and framed.  It would make a nice accompaniment to your vintage stereo.