This is the same newsprint we use when we are packing orders, but we've also been taking it home to print proofs and make damp packs for years. It finally dawned on us that you might like to use it too, especially since it is very inexpensive compared to the newsprint sold in art supply stores.
30# newsprint, smooth on both sides, takes ink very well. It is not acid free. Made from recycled paper.
Since it is meant to be packing material, the supplier is not too careful about cutting the huge sheets exactly to size, so it is approximately 18" x 24" give or take about half an inch.
Sold by weight. 3lbs is approximately 100 sheets, 1.5lbs is approximately 50 sheets.