I thought I would do a little comparison of (SaS) Steam-A-Seam 2 fusible tape (1/4") with (SW) Stitch Witchery Tape (5/8" in light and normal.) I applied each product between 2 strips of 100% cotton fabric according to manufacturers' directions. When cooled I pulled strips apart half way to check bonding--then I washed them--and repressed and checked bond again.
All of them bonded well and when pressed after washing--they all maintained a good bond and "rebonded" where I had pulled them apart. For Applique you need to have a pressing cloth for both products to protect your iron from residue. Both come in different widths--SaS in 1/4" and 1/2"--SW in 1/4", 5/8", 1", 2" in light to heavy.
My Preference is the Steam-A-Seam and here's why:
Only Steam-A-Seam is a little tacky to help it stay in place as you get ready to press. (although it sticks better if you warm the cloth with an iron before pressing the sticky side on.) Also it is a bit less stiff after fusing than SW.
Steam-A-Seam is applied in 20 seconds with a warm iron, while the Stitch Witchery tells you to use a damp cloth and steam and a little bit more time.
I also prefer 1/2" to 5/8" size for wider uses and IF you get the 1/4" SAS it comes in 40 yard packs compared to 20 yards for the SW. 1/2" SAS is also 20 yards.