When you need a long, flexible measuring tape but are stuck with only a ruler, use simple items from around the house to make your own custom tape measure. Make your DIY tape measure as long as you need for your particular project. Use ribbon made out of a smooth surface that you can write on, such as vinyl or plastic, and choose a fabric that will not fray if you would like to keep your DIY tape measure for future use.
Lay the ribbon on a flat surface at least 12 inches long.
Align your ruler with the edge of your ribbon, being careful to keep the edges lined up and even for the most accurate measurements. If you are using a printable tape-measure template, you can either tape the printed template to your ribbon and use as your tape measure or use it like a ruler to make your own markings.
Make a line mark every inch on your ribbon, marking each inch with the appropriate number.
Continue marking inches until you reach the end of your ribbon tape measure.
Allow marker to dry completely before using your DIY tape measure.