They are really easy to use. They are clear plastic folders that have a brass stencil (which sandwiches above the cardstock) and a raised plastic piece that forms the positive that goes with the stencil (this goes against the "bottom" of your cardstock). It works pretty much like a Cuttlebug embossing folder-- I even use the same sandwich of A, B, folder w/ cardstock, B. The impression is not quite as deep as the Cuttlebug folders, but definitely visible. You can try to add a thin shim to the sandwich, but because there is a brass stencil as part of the folder, it may end up cutting into the cardstock. I would test it out on some scrap cardstock to find the right sandwich for your machine, since each one is wound a little differently.
Another cool thing, is that the brass stencil and the raised plastic piece are both removable (stuck down with double stick adhesive) so you can move them around in the folder in case you need to re-orient them. You can also use the brass stencil to aid in coloring or use it to trace the shape.
I ordered a ton of different ones from the Sizzix outlet when they were on sale, and I think they are worth it for the price of around $1 each.
Embossed Letters/Monograms
