Are the number and color name printed on the marker?
Yes, this is correct. Each marker is named and numbered.
Is the ink oil-based, alcohol based?
No, but they are easy to work with and are water based.
Do these work on clay pots/wood?
No. They are water colors for paper, cardboard,etc.
Are they nontoxic?
They are ACMI certified non-toxic products that meet the requirements of quality and performance standards.
What is the difference between 100 white and 100 black?
Just the color of the plastic on the markers. The ink itself is the same.