The cut vinyl decals are all cut individually, with no "backing material" that stays on the model. For instance, the "X-20" emblem in the white area at the front of the rocket is actually four individual pieces of black vinyl (the "X", the "-", the "2", and the "0") with no clear material connecting them together. When the arrive for application, the decals or on a backing sheet, with a covering sheet (that is somewhat "see-through" like tracing paper covering the tops of the decals. What you do is cut out the decal to be applied - in the "x-20" emblem example it's actually four decals that are arranged correctly - and remove the backing paper from the adhesive side of the vinyl. The top sheet remains in place to hold them in the correct arrangement. Then you wet the area to be applied with a squirt bottle filled with tap water and a bit of liquid dish soap. Apply the decal to the wet area (the water/soap mixture allowing you to slide it into the correct position) and then rub out the water and air bubbles. Let set awhile for the backing adhesive to grab to the model, and then carefully remove the top cover.
I got two sheets that were approximately 12" x 24" in size. This could have been reduced, because there was plenty of empty space on the sheets. I suspect that the decals could be of very substantial size, not limited by pre-made decal page sizes. Well, I'm sure there's some limitation, but I don't know what that size is.