Some backings need to be sealed or otherwise treated before adhesive coating. Plastic "codice 1 keys" with adhesive backings are available as novelty gifts. Paper backings without wet strength may release their adhesives, potentially contaminating recycling efforts. Choice of backings, coatings, adhesives, and liners can be strong factors. There are generally two types of backings, poly backing and mass backing. Modacrylics are also used in fleece, knit-pile fabric backings, and nonwoven fabrics. The Scotch brand includes many different constructions (backings, adhesives, etc.) and colors of tape. The series "Art Brothel" consists of 25 photographs of various sizes with plastic laminate backings. Unobtrusive backings allow the often breathy voice of Louisan to remain prominent. In 1856, he was granted his first patent for wire brushes with ornamental backings. The ballad "Out from Under" incorporates acoustic guitar backings. The vocal backings on both songs were provided by the Jordanaires. This phenomenon occurs because of the high electrical resistivity of these film backings. The backings for the altars in churches (reredos) can be embedded with niches for statues. A few have backings that limit the dipole radiation pattern.