What is the difference in fabric? *Knit- a mid-weight cotton fabric such as used for t-shirts and little girl dresses. Very soft,2 or 4-way stretch and static free. *Thermal knit- OUT OF STOCK- soft cotton with 4-way stretch for a comfortable fit. This fabric is what is used for long underwear. It supplies warmth without being overly warm. This fabric will not collect static. Due to the large amount of stretch a less stretchy material will be used for the collar and cuffs to help retain the shape of the garment. *Sweatshirt: Very warm knit just like your favorite sweatshirt. Static free. *Velour- Warm and cuddly, nice stretch and static free, similar in warmth to fleece. *Smooth velour- Warm cuddly fabric with 2 way stretch and static free. This fabric is thinner than regular velour which is often found in lounge wear. *Fleece- 20% off as I am discontinuing this fabric. A warm synthetic fabric with 2-way stretch. I am just about out of fleece. I do have some odds and ends of prints and solids. If you are willing to accept a surprise contact me with the color of your dog for additional options.