Lines are solid and not blurred and won't erase off if using pencil. Writes smooth with pencil pen and sharpie. Though with Pilot G-2 .07 ink pens the paper doesn't absorb gel all that great so beware if using for book marking. Using Sharpie professional series doesn't bleed through to lower sheets even with slow handwriting; though able to read from reverse side. sticks well even after several back and forth replacements from glass to paper and dry erase boards.