I don't use space bags, A cheaper way is to buy Hefty 2 1/2 gallon zippered food bags. They are quite large. You can pack a whole outfit in each one. Slacks, blouse, light weight jacket, or sweater and underware. You can put pressure and squeeze out all of the air and flatten the package out. It is so easy to have everything to wear at hand and can keep the luggage neat too. Hope this idea helps.