Spoonflower recommends using a phosphate free laundry detergent when washing their fabrics. This picture at left shows why you should believe them.
I disbelieved them and look what happened to the fabric printed on voile that's in the bottom of the photograph. The voile in particular resents being washed in a washing machine with washing machine detergent that has phosphates in it.
Hand wash the voile in a phosphate free detergent.