There are no mistakes in Zentangle, so there is no need for an eraser. If you do not like the look of a stroke you have made, it then becomes only an opportunity to create a new tangle, or transform it using an old trusty pattern. A Zentangle tile is meant to be a surprise that unfolds before the creator's eyes, one stroke at a time.
Every soul innately yearns for stillness, for a space, a garden where we can till, sow, reap, and rest, and by doing so come to a deeper sense of self and our place in the universe. Silence is not an absence but a presence. Not an emptiness but repletion A filling up.