Scoring is creasing a paper for the purpose of making folding easier. If you were to take a sheet of card stock and try to fold it in half, it would look cracked and uneven, and pretty much not very attractive at all. But when you score a sheet of card stock, it indents the paper where it is intended to fold, giving a nice clean and even crease without the cracks.
In the past, whenever a customer ordered a job that needed to be scored [cards, booklet covers, table tents, pocket folders, etc] we were setting up and scoring these jobs by hand. Even though it proved as a pretty decent arm workout, it was very time consuming. But, good news! We recently obtained a new Auto-Creaser that scores jobs over 10 times faster than before, and just in time for our yearly slew of Christmas and New Years card jobs. With this new machine, we can finish folding job faster and more efficiently.
Another benefit of this machines is that it can even helps text weight papers look better. Text weights can be folded without scoring because they are light weight sheets. Unfortunately, for many small quantity jobs that are printed on digital copiers, there can still be cracking where the artwork meets the fold. As you may or may not know, copiers lay toner (a polymer/plastic) on top of the paper. Because it's not a real ink and hasn't soaked into the fibers of the paper, digital will crack when folded. Scoring these jobs — especially brochures — dramatically improves the look and quality. Once you see the difference you won't ever want to go back to the old way again.