They are called Custom Imprintand I prefer the 1 inch wide White ones.
Yes, they cost a little more but they are well made, easy to use, and look soooo nice standing in a little row on the shelf. I use the spine label in all caps to tell the name of the unit and then on the front I put the title of the block, whether it's Head, Heart, or Hands, and when I taught it. I put all my lesson plans and notes in there and it's great. For example, with the Baking unit (3rd Grade Maths of Practical Life) I can add all the recipes that we used, or stash away a recipe for future use if I see one and think, "This would be great for the Baking block." I was reading King Beetle-Tamer: And Other Light-Hearted Wonder Talesto my students the other day and, when we came across the chapter titled "New Days, New Ways," I thought this would be perfect for our Microscope Studies binder! So I went and got the Microscope Studies binder off the shelf and wrote myself a note for next year.