Fitting issues do happen with elastic. Following the pattern directions should give you accurate results but you may discover that after you wear the garment for a bit, the elastic becomes too loose. You can solve this problem by stretching the elastic a couple of times before you make a final measurement to cut the elastic. By stretching it and allowing it to relax you will have a more accurate fit to start with, than cutting the elastic that may have sat untouched for an extended length of time.
Almost all elastic will say that it will withstand temperatures to two hundred degrees. Anyone who has invested in expensive lingerie will say that they do not machine dry the lingerie, believing that the heat of the dryer will shorten the life of the elastic. How hot your hot water is, or the "sanitize" mode on your washer gets, can be adjusted before you wash items with elastic. Machine drying your items with elastic in them, is a decision only you can make but just as a dryer filter fills with lint form the clothing, there are high temperatures that may effect the life of the elastic.
Sewing machines vary and so does their performance when sewing directly on elastic. Even when you are using a woven fabric, you may need to use a ballpoint needle when sewing the elastic onto the fabric. If your thread is knotting and bunching, you may need to change to a sharp needle, even on knit fabric. Everything You Need to Know About Sewing Machine Needles
When sewing elastic to fabric, use a stretch stitch or narrow zigzag stitch so the stitching will stretch with the elastic.
Store your elastic out of direct light, especially sunlight and in a cool location. Extended light and heat will effect the lifespan of your elastic stash. Many people wrap elastic around cardboard rolls suck as paper towel or toilet paper rolls. Do not stretch the elastic as you wrap it on the rolls. Use no tension on the elastic as you wrap it on the roll.
"How wide should the elastic be?", is a very common question. Here are some rules of thumb to follow:
- Waistbands -- 3/4" to 1" wide from most garments. 1/2" maybe wide enough on lightweight children's clothing.
- Necklines- 1/8" to 1/4"
- Sleeves -- 1/8" to 1/2"
- Swimwear -- 1/4" to 3/4"