An authentic vintage Japanese double-sided porcelain enamel advertising sign for Hishi Plate (ヒシプレート), manufactured by Nagahama Rubber Co., Ltd. (長浜ゴム工業株式会社). The sign features a clean and distinctive mid-century design with bold red 「ヒシプレート」 lettering set against a white background, complemented by blue vertical stripes and the company’s original logo. The inscription 「波板 販売店」 (“Corrugated Sheet Authorized Dealer”) identifies this as an official retailer’s advertising sign. Its crisp typography and strong geometric composition are characteristic of Japanese commercial signage from the Showa era, making it an excellent display piece for collectors of industrial advertising. Both sides retain their original porcelain enamel finish. The sign shows light age-related wear, including minor enamel chips, scratches, edge wear, and small areas of oxidation, while preserving vibrant colors and excellent gloss. A highly collectible example of Japanese industrial advertising and a wonderful addition to any collection of enamel signs, hardware store memorabilia, or Showa-era décor. Estimated date: c.1960s–1970s Material: Porcelain enamel on steel Dimensions: * Width: approx. 45.5 cm * Height: approx. 30 cm Condition: Original vintage condition with minor enamel loss, scratches, edge wear, and light oxidation consistent with age. Please examine all photographs carefully, as they form an important part of the description. Keywords Enamel, Sign, HishiPlate, Nagahama, Rubber, Japan, Showa, Vintage, Advertising, Porcelain, Steel, DoubleSided, Industrial, Hardware, Dealer, Corrugated, Collectible, Retro, Memorabilia, Antique