Yes! Prewashing will not ruin the fabric, and it will preshrink your fabric. If you do not preshrink the fabric, your poor gift recipient will see the item warp when THEY wash it for the first time. Unless you are making a rag finish project, which is laundered AFTER construction, prewash all fabric. Zigzag or apply FrayChek to the cut edges of the fabric before you wash it to minimize unravellilng in the wash. Use a gentle cycle and dry as you would for the finished item.

You will wash out the manufacturer's sizing, which is easily replaced (giving the item a crisp feel) with a quick ironing with spray starch once the item is completed. The starching makes the item look new and unwashed.

Cheers,
Janet