Paper bags are versatile materials to use in practical household purposes, storage and transportation purposes, and in crafts. Stiffening an ordinary paper bag with liquid fabric starch and tying with raffia, ribbons or other seasonal wrappings can create delightful packaging.
Place the plastic dust sheet onto the floor to completely cover the area in which you'll be working. Keep the towels handy for cleanup.
Pour the liquid fabric starch into a plastic container large enough to fully immerse your paper bag.
Immerse the paper bag into the liquid fabric starch, gently, so the wet starch does not tear the paper.
Hold the bag with one hand to keep it upright while you stuff, with the other hand, as many plastic grocery bags into the wet paper bag as are needed to keep the bag upright and retaining its natural shape. A box that fits inside the bag is good too, but make sure you wrap it with cling film first or the box will stick to the paper bag.
Allow the paper bag to air dry until completely dried and stiffened, about 24 hours.
Remove the plastic grocery bags or plastic-wrapped box from the stiff paper bag. Decorate the stiffened paper bag if desired.
You can fold the edges of the bag down prior to immersing in the liquid starch if you'd like a folded look to your dry, finished stiffened bag. Don't confuse liquid fabric starch with spray starch. Liquid fabric starch comes in gallon or larger pourable containers.
Don't stuff the wet paper bag with anything made of paper unless it is covered with cling film first. The drying liquid starch will stick to anything paper and might tear if you try to remove it once the bag is stiffened and dry.