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Before you assemble the back-drop, measure its length and width. Mark the dimensions of the back-drop with a light pencil mark, chalk, or a piece of tape. The back-drop may be as large or as small as you’d like—it will really depend on the space you’re using and how you intend to capture the back-drop on camera. Ask yourself the following questions: Do you want to take full-body shots or will the pictures be from the waist up? How tall are your guests? How many guests do you want in one picture? Stretch a piece of masking tape—sticky side out—along the top edge of your back-drop from corner to corner. To secure the tape to the wall, cover each end with a piece of masking tape. The streamers will hang from the sticky side of the tape. Attach streamers to the masking tape from left to right. Roll out each streamer to the desired length and cut it in a straight line. As you move from one corner of the back-drop to the other, layer the streamers slightly and vary the colors. Don’t worry about cutting every streamer to the same length. You will trim them later. Place pieces of rolled masking tape along the top edge of the back-drop. Roll a single streamer along the top edge of the back-drop in a straight line. Cover the two small vertical pieces of tape on each end in the same manner. This will give the top of your back-drop a clean, crisp edge. Stretch a piece of masking tape—sticky side in—across the bottom edge of your back-drop. Attach each end of the tape directly to the wall. This piece of tape will prevent your streamers from moving. If you want the streamers to move with the breeze, don’t tape the streamers to the wall. This will provide you with a less structured, and perhaps more whimsical backdrop. With a pair of scissors, carefully trim each streamer near the bottom edge of the tape. You will cover the bottom with a streamer, so don’t worry about trimming each streamer perfectly. Stick several pieces of rolled masking tape along the bottom edge of your back-drop. Roll a single streamer along the taped edge in a straight line. When the backdrop is done, you will have a solid rectangle or square of crepe paper to pose in front of. You can add two small vertical streamers to each corner so that it matches the top.

Summary:
Determine the dimensions of your back-drop. Attach a piece of masking tape—sticky side out—to the wall. Stick streamers onto the tape. Cover the top edge with a piece of crepe paper. Tape the bottom of the streamers to the wall. Trim the streamers just below the edge of the tape. Cover the bottom edge with a piece of crepe paper.