A lot depends on if it is an iron on -interfacing. Check for little dots or a shine on one side. You can also take a small piece and iron it to a piece of fabric.... but make sure to use another scrap of fabric between the interfacing and the iron so if its Iron -on and you have it the wrong way it will not be stick to your iron.
If it is iron on use the steam setting on your iron..... and just hover it over the interfacing letting the steam relax the crease. If its not iron on you can do the same , or reduce the iron temp lower and iron the interfacing directly. Most interfacings have a large poly content so direct contact with the iron at a high cotton setting will melt the interfacing.
An interesting note.... Pellon makes craft interfacing and garment interfacing... the biggest difference is the craft interfacing has a rayon content and will shrink.
Last edited by Lori S; 05-25-2015 at 05:29 AM.