Five Green Acres
It just so happens that, in their infinite wisdom, the creators of The Pencil engineered the distance between two pencil tips held side-by-side to equal 1/4.” As they were no doubt good friends with the engineer of the standard sewing machine foot, the two parties concurred that 1/4″ was indeed the divine proportion, forever marrying the utility of pencils to the needs of sewing.
So you have a pattern that does not include a seam allowance? Problem solved. Two pencils and a few pieces of tape are all you need to add 1/4″ to the pattern before cutting your fabric. Simply trace the innermost lead along the perimeter of the pattern and the other lead will add an adjacent line 1/4″ from the pattern’s edge. You could trace directly on to the fabric or on to a larger sheet of paper, making a new pattern piece.
This is also useful for making your own patterns, as long as you roll with a 1/4″ seam allowance. If not, dig deep into your school pencil bag and pull out the compass you haven’t used since geometry class and measure and mark your desired seam allowance width.