Hi I am LINNY from Manchester N.H I am new to quilting and decided to make a rail fence quilt .I want to know if you can help me.I bought some 2 1/2 inch jelly rolls from joann's to make a rail fence quilt every time i sew them together and try to cut a 6 1/2 inch square it is always short by 1/4 inch.when i sew it i use 1/4 inch foot.Could you please help me.Thanks