Hello Mew, this is a satin costume, so, please put it into the cool water for about 10 minutes first, then take it into warm water (with softener) and use hands to wash it gently. (n__n)
A: Most of our costumes are polyester costumes, so you can simply take them to professional dry clean store after wearing them; or, you can wash them:-
(1). Hand washes only, using warm water (or normal, just don't be so hot or cold) will be okay.
(2). For most of them (except leather, fur & materials that are thin, light or weak), you can iron it (like ironing normal clothing) when they are dry.
(3). It will be better for you to wash them separately, because costumes' colors are always being sharp & bright (like red, yellow, purple, green, etc). So please wash them separately, because this type of colors may mix color with other clothes or costumes.