Originally Posted by Quiltmaniac

It stands for integrated dual feed (I don't know where they get the "T" from).

If you have ever heard of a walking foot attachment, it's the same idea, but it's permanently fixed to the machine, although you can disengage it if you need to. It feeds the two layers of fabric evenly whereas without it, the feed dogs feed the fabric through faster than the top layer feeds through (or is it the other way around?).

I have the Margaret Islander sewing tapes and she demonstrates by sewing together two pieces of fabric, each 45" long. She begins with them even at the top, sews a regular seam, and when she gets to the bottom of the strip, the bottom piece extends by about an inch beyond the top piece. She then demonstrates it again, this time holding the strips up at an angle so that the bottom piece isn't being pushed along by the feed dogs, and at the end they are even! (i.e. she "eases" them in togethe)r.

Still, you can't do this with a couple of 2" squares you are trying to sew together.

I had a machine before the Pfaff for which I purchased a "walking foot" but it didn't work nearly as well and it was also very noisy!

I love my IDT!