I just opened up a box of XP2 (135 x 100') and discovered that Ilford supplied 20 pre-printed cassette labels with the roll. When did they start doing that? It's pretty cool!
My current roll of HP5+, bought a few months ago, didn’t come with labels. I print my own with my little Brother label printer (no DX coding, but I don’t need it).
I used to print sheets of labels for bulk loaded film, one label each for the film cassette and one for the black Kodak tub. Now I just use masking / painters tape and a Sharpie. Tape comes off easily for re-use of the cassettes.
If you are going to print labels on a computer, make sure you don't buy permanent labels as they are a bear to remove and clean up the adhesive. Look for labels marked as removable.