Original insulation trade vintage catalog for THE MACALLEN COMPANY, was located at 25 Macallen Street, Boston, MA. Manufacturers of insulating materials and electrical specialties. Compressed sheet mica, papers, cloth, tubing. insulation. India and Amber mica is used in the sheets, bound together with a suitable cementing material and then compressed and baked. Unbound from a large 1943 architectural catalog, this unique old one page technical specifications brochure would exhibit beautifully matted and framed. A fantastic addition to your retro insulation collection. Page is detached and may contain a small amount of residual glue on edge.