How to Measure Welting

Measuring Welting Length

• 1

  Measure the perimeter of the item you plan to trim, using a cloth measuring tape. For example, if you're trimming a pillow, measure the seam joining the front and back panels of the pillow, bending the measuring tape around the corners to keep the measurement accurate.

• 2

  Calculate the perimeter of items that haven't been constructed yet using the pattern. For example, if you're making the pillow from scratch, add the lengths of each seam in the pattern to find the total length of the perimeter. Remember to use seams for your calculations rather than edges -- if you add the edges of both pieces of fabric you are joining, you'll count the seams twice. Add an extra inch for each corner on large items or half an inch for each corner on small items.

• 3

  Add an extra three to five inches to the total for safety. The more spare welting you have, the less likely you are to come up short.

Measuring Casing Width

• 4

  Measure the diameter of the welting cord. Multiply it by 2. For example, if you are using 1/2-inch cord, multiply 1/2 inch by 2 to get 1 inch.

• 5

  Check the pattern to learn the project's seam allowance. Multiply it by 2. For example, if the seam allowance is 5/8 inch, multiply 5/8 inch by 2 to get 1 1/4 inches.

• 6

  Add the two results to determine how wide to cut your bias strips. In this example, add 1 and 1 1/4 inches to get 2 1/4 inches. This is how wide your casing fabric should be.