Yes! Machine wash on COLD and then air dry. You don't want the cotton to shrink.
11" x 17"
The bag is made from mesh, which means they are VERY breathable. Produce like apples, oranges, cucumbers and similar items that have a robust peel are great to keep in the bags. Items like carrots and leafy greens are better kept in something more protective and less breathable, like a beeswax wrap or a jar of water.
It completely depends on which store you go to. More and more stores are getting on board, though! If not, it's easy enough to take the produce out of the bag as it goes through the weigh scale.
The bags are made from 100% organic cotton and will biodegrade.