And, of course, a large number of libraries generate lettering by computer. Libraries list engraved plastic laminate and vinyl letters on acrylic, plastic, or Plexiglas as the most durable materials for signs. The staff at most libraries walk through the building to decide where signs are needed, but it is interesting to note that many libraries make this decision by incorporating user input as well. Libraries also monitor users' directional questions, allow a committee to decide, or simply respond to library staff requests when making decisions about where to place signs. Libraries combat vandalism by using reverse engraving on signs, placing vinyl letters on the reverse side of Plexiglas, installing Plexiglas over signs, or laminating signs.
Several libraries place signs only in high traffic areas where vandalism is less likely to occur.
Temporary Signs One respondent correctly notes that all too often there is a discrepancy between the guidelines and actual practice. Temporary signs are especially difficult to manage. In six libraries temporary signs must conform to the same guidelines as permanent signs. Several libraries have guidelines specifically developed for temporary signs, but 44 libraries have no restrictions or guidelines whatsoever. Some libraries simply do not allow hand-lettered signs, and others require that even temporary signs must conform to colors representative of the building.