Shank Button – A shank button is one that has the attachment mechanism, usually a loop, on the back of the button instead of being attached to a garment through holes in the face of the button. Shank buttons are frequently used on jackets and garments made from heavy fabrics because the gap provided by the shank allows the fabric being buttoned to lie more smoothly under the button. A shank can be added to a standard button with thread by sewing the button on with a gap between it and the garment surface and then wrapping the sewing thread around the loop underneath the button. An easy way to add the gap is to insert a pin or toothpick (depending on how long you want the shank to be) between the fabric and the button before sewing on the button. Be sure to reinforce the thread and fasten it securely.
Shirring – This technique is done by sewing multiple parallel rows of stitches that are gathered to create a section of evenly gathered fabric. Shirring can also be done using elastic thread that gathers the fabric as it is being sewn. Using elastic thread allows the gathered area to stretch. You can also purchase pre-shirred fabric. Elasticized shirred or smocked fabric is perfect for making simple tube tops, dresses or skirts. Just cut it to fit the circumference of the body and sew up the side seam.
Sizing – A fabric finishing agent that adds body and crispness to fabrics, making them wrinkle and soil resistant. Most ready to wear garments are treated with sizing to make them look better on the hanger. Sizing is available in spray form for using at home and is most effective on synthetic fabrics (starch is more effective on natural fibers).
Sleeve head – An extra piece of fabric that is sewn into the top of the armhole to support the sleeve. A sleeve head allows the sleeve to curve slightly as it comes out of the armhole rather than dropping straight down, giving a nicer line to the garment. This technique is primarily used in jacket and coat construction.
Slit – A slit is an opening in a seam of a garment to allow freedom of movement. Slits are commonly seen in fitted skirts and can be placed in front, back and side seams.
Sloper – A sloper is a basic pattern upon which other garments are designed. A sloper encompasses basic measurements for a garment size or individual and includes only wearing ease, not design ease or seam allowances. A complete sloper set for a woman includes a bodice front and back, a set-in sleeve, and a straight skirt. Having a customized sloper can greatly assist in altering patterns to address specific fitting issues. For this reason, making a sloper is on my sewing to-do list.
If you would like to learn more about fitting or couture techniques, here are some highly regarded books on those topics: