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If you own your own business or manage one with set hours of operation, an open sign will let your customers know that you are open and ready to serve. While many business and office supply stores offer generic open signs made of either simple poster board or plastic with lights in them, you can make your own sign using lightweight, but sturdy, foam core board and a few other supplies.
Cut a foam core board to the size and shape you want for your sign. Use a straightedge or ruler with your utility knife to make sure that the cuts are straight.
Use a hole punch or hand drill to cut a 1/4-inch to 1/2-inch hole in the center of the top edge of your sign. Cut it about 1 inch from the edge of the board. This will provide a way to hang your sign.
Write the word "open" on one side of your sign and "closed" on the other, using letter stencils and a pencil. Use stencils that have letters that are at least 3-inches tall, so they can be seen easily from the street.
Follow the pencil lines with a permanent marker, filling in the letters completely for a bold look. Avoid yellows and other light colors that could make your sign difficult to see. Black or red may be best, as they are rich and bold.
String a piece of yarn through the hole to create a loop that can hang over hardware on your door or window. Alternately, you can attach a suction cup hook to your front door or window to hold your sign.
Ashley Kurz, a full-time professional writer since 2009, publishes on various informational websites. An expert in the craft field specializing in craft-related topics, Kurz has taught arts and crafts for group therapy sessions.