Originally Posted by janRN
Another foot I really like and has made a big difference in my accuracy is the quarter-inch foot. It has a metal side thingy that the fabric butts up against. I had marked the 1/4inch with tape and post-its but for some reason this works great. I think it was $19.99 for my Viking but I'd pay double that now that I can see how much more accurate my seams are.
I believe what you are referring to is a 1/4 inch foot w/guide. It has a plate that keeps you from having the fabric go outside the 1/4 in space, unless you want the guide jutting into your fabric. It's one of those feet that's great, but annoying when you want to do something that doesn't involve a 1/4 inch seam exactly - I find myself having to change it all the time...