Shank ons have a hollow protrusion on the back through which thread is sewn to attach the button. Button shanks may be a separate piece added to the back of a button, or be carved or moulded directly onto the back of the button, in which case the button is referred to by collectors as having a 'self-shank'. This is a common construction for older shell and glass buttons, for example. Buttons with shanks have no holes in the button blank (the main part of the button) itself because they are not needed for sewing. Buttons with shanks are more expensive to produce than shankless buttons.
Sewing Sew-Thru Buttons Use a double strand of thread. Knot the end. Take a small stitch on the right side. Take a second stitch in same place. Bring needle and thread through one hole in button. Center button over stitch. Insert needle into another hole in the button and into the fabric. Pull through. Slip a toothpick, needle, or pin between thread and button to form shank. Take 3 or 4 stitches through each pair of holes. Bring needle and thread to right side under button. Remove toothpick, needle, or pin. Wind thread 2 or 3 times around button stitches to form shank. Secure thread in fabric under button by making a knot or several small stitches.
Sewing Shank Buttons Use a double strand of thread. Knot the end. Take a small stitch on the right side. Take a second stitch in same place. Bring needle and thread through hole in shank. Center button over stitch. Insert needle into fabric and pull through. (If length of shank is not sufficient, place a toothpick, needle, or pin under shank and continue as for sew-thru button.) Bring needle and thread to right side. Take 3 or 4 stitches through shank. Secure thread in fabric under button by making a knot or several small stitches.
Continue to feed the needle into the button from one side and then the other. Do this six or seven times until you are satisfied that the button is attached properly. Now on the wrong side under the button, make a knot by sewing into the material and making a loop with the thread, several times. When you feel confident that the thread won