The Revenue Act of 1862 required manufactures of proprietary medicines, perfumes, and playing cards to affix revenue (tax) stamps to their boxes or packages as evidence that the tax had been paid. These companies were allowed to have special dies engraved and plates made, at their expense, for their exclusive use. The manufactures recognized the value of customized stamps with distinctive designs for building brand recognition and customer loyalty. A few hundred stamps with very interesting designs resulted which are called the private die proprietary revenue stamps. Not really, though, most collectors refer to them as the "Match & Medicines."
This 4c stamp, Scott #RS249, was used by the S.R. Van Duzer company of New York for its hair restorer product.
The blue lines you see are silk threads; many of these stamps were printed on silk paper as a deterrent against counterfeiting.