What type of specialty curtain is see-through and appears solid when lit from the front?

The correct answer is a scrim. A scrim is a type of specialty curtain made from a lightweight, translucent fabric that allows for interesting visual effects in theatrical productions. When lit from the front, a scrim appears solid, creating a seamless backdrop or surface. This characteristic makes it an effective tool for scene transitions or to enhance atmospheric effects, as it can obscure what is behind it while giving the illusion of a solid structure.

When lit from behind, however, the scrim becomes transparent, revealing whatever is located behind it. This dual property allows for creative storytelling techniques, such as revealing or hiding elements of a scene depending on the lighting used.

Other options, such as a traveler, cyc, or backdrop, do not share this distinctive property. A traveler is typically a curtain that opens from the center and moves to the sides, while a cyc (cyclorama) is used mainly for creating a backdrop that mimics the sky or light effects and generally does not have see-through properties. A backdrop, used primarily for scenic painting or visual design, does not exhibit the same lighting effects as a scrim.