Dip coatings of transparent colors that
are given an overcoat of acrylic are an
improvement over the sprayed lacquers;
they yield a similar result with a higher resis-
tance to abrasion and weather. These plas-
tic-coated lamps offer more sparkle, greater
brightness, and higher saturation for any
given color.
Colored 50R20, 75R30, and 150R40
lamps are manufactured with fired enamel
finishes. Colored 100PAR38 lamps have a
coating of dye-impregnated silicone plastic,
similar to the plastic-coated sign lamps.
Colored 150PAR38 lamps have dichroic
interference filters that are vacuum-depos-
ited on the inside of the cover lens. The filterINCANDESCENT LAMPSFigure 6.14Interference (dichroic) filter.