Pellon 987F Fusible Fleece is the recommended substitute for H630, but I think that it's more suitable as a substitute for H640. It's denser (more felt-like) than both of the Vilene fleece/wadding products, and the effect on the fabric is much heavier. It creates much more structure (and thickness) than the light "oomph" that H630 gives to fabric.
You can see the difference a bit more clearly in profile... That's the Pellon fleece between the H640 (back) and H630 (front).
I'm not sure what to suggest to use as a substiute for H630 (light fusible fleece). I'd welcome any suggestions from those of you in the USA (or other non-Vilene H630 territories), if you've found something to do the trick.
Fast2Fuse, Peltex and TimTex are all stiff, compressed-fibre interfacings, of diffferent densities and fusible properties. Below, we have Heavyweight Fast2Fuse at front, TimTex in the middle and Peltex 71 at the back.
Fast2Fuse comes in a Regular weight and Heavy weight. I tend to use the Regular weight on the outside of bags and purses that I want stiffened (often with a layer of H630 between the fabric and the Fast2Fuse), and it's also handy for zipper tabs and some of the fancy new (secret squirrel) things I'm currently working on. I use the heavy-weight when I want real box-like structure, or stiff bag bases.
I've done a comparison of Fast2Fuse and Peltex before. For bag bases, Peltex is perfectly interchangeable with Fast2Fuse. For finer work, I'd seek out Fast2Fuse if I could, and opt for Peltex if that's all I could find (2nd choice). Peltex has the advantage of being available in both double-sided and single-sided fusible, as well as non-fusible. Fast2Fuse is double-sided, which isn't always convenient. Swings and roundabouts...
TimTex is about as thick as Peltex, but slightly denser (crisper?) and not fusible. You can use it with fusible webbing (Vliesofix/wonderUnder/Bondaweb/Heat'nBond/Steam-a-Seam) to fuse it to fabric, or wrap it in fusible interfacing to make bag bases.
You can see the different densities and thicknesses in the profile shot, below.
Vilene S520 is an easy one. It's almose identical to Pellon Deco-Fuse.
Vilene S320 is one of my most-used interfacings, and unfortunately, I can't find an exact substitute for it.
I love that the embossed surface of Vilene S320 breaks that 'cardboard' surface effect that most non-wovens have, but apart from that property, it can be substituted with Pellon Craft Fuse. Like S320, Craft Fuse fuses at low temperature and stays stable, and it gives about the same amount of support to the fabric, and it can be used in conjunction with fusible fleece.
I've only listed Vilene and Pellon products.... but there are other brands out there, and I don't have access to all that are on the shelves in the USA or Europe.
I'd like to open up the floor to any of you who'd like to offer any other suggestions. If you have anything that you feel might be useful, please feel fre to share it in the comment box below...