Theatrical lighting gels are sheets of colored plastic that are placed over the front of a lighting instrument to change the color of the light being cast. Since the heat of the lights eventually destroys gels, they must be replaced on a regular basis. For this reason, it's important for any theater technician to know the proper process and technique for making individual gels from the large sheets of gel plastic that are sold by manufacturers.
Instructions
1. Obtain the correct measurement for the gel you want. If you have any old, burnt out gels for the light instrument you're fitting, measure these, or look at the gel frame that fits the instrument and measure the outside of the frame; the gel will be the same height and width.
2. Examine a sheet of gel plastic to find a good place from which to cut your square. Avoid any holes, bent or wrinkled spots, or areas that might have already been misshapen or discolored due to accidental heat exposure or improper storage.
3. Measure and mark the gel plastic for cutting. Make small marks for height and width using your white grease pencil. Make the smallest marks you can (do not draw full lines).
4. Cut the gel. Line up the edge of the plastic sheet with the rear measuring edge of the paper cutter and line up the pencil marks with the blade edge. Pull down the arm of the paper cutter firmly. If you encounter resistance, press the arm in the direction of the body of the paper cutter. Handle the gel square by its edges to avoid fingerprints.
5. Mark the gel with its specific color information. In small letters on one of the gel square's edges, write the initials of the manufacturer (such as "R" for Roscoe or "GAM" for Great American Market) and the manufacturer's number for that color. These numbers are standard enough that lighting designers use them for creating light design plots, so you want to ensure that each newly-cut gel can be identified and stored correctly.
6. Place the gel square inside the gel frame. Open the frame and line up the edges of the gel with the edges of the frame. Close the frame. If it's a metal frame, firmly press the folded edge of the metal to keep it from popping open.
