If you're me and you've been on tumblr, you've been seeing tons of neat galaxy printed items, but at really ridiculous costs! (200$ for a printed minidress? Really?) I can't seem to actually find any of the fabric. I've checked just about everywhere, and aside from some really low-res spoon flower options, there really isn't any other option but to DIY it. This technique uses a combination of tie-dying, bleaching and painting techniques. All the supplies can be found at any local store.
You will need:
-Object you want to galaxy. (this can be anything, though I use a black 100% cotton tshirt for this. Because this tutorial uses bleach, any material you can bleach and paint will work. Even flat yardage is fine. Dark colors like navy blue and purple will work fine too. This would be a very nice effect on a pair of denim jeans)
-Bleach
-Spray bottle
-Rubber bands
-Acrylic paint
-Textile medium
-Paint brushes and sponges
The first step is to take your shirt and wrap the area you want to bleach with rubber bands. I suggest you make it as random as you possibly can. Do this on both sides of the shirt. Dilute your bleach and spray it on. Leave it until you can get your desired results, remove the rubber bands, and then wash your shirt completely using a detergent. Air dry. (If you note, I did rip a hole in my shirt with a pair of scissors taking the rubber bands off. Don't do that.)

After this, your shirt will look like so. The lines around your bleached area will be strong and somewhat jagged. The next step is to bleach your shirt yet again. And again. Keep bleaching and washing your shirt until you get your desired look. Just make sure that you do not bleach it until the point where the fabric becomes weak.
(after one bleaching)

(after second bleaching)

(front of shirt after final bleaching)

(back of shirt after final bleaching)

Once your shirt is bleached you should start looking up photographs of galaxies. I highly suggest using the hubble telescope
(
http://hubblesite.org/gallery/) website. This is where a brief knowledge of astronomy might help you a little bit. Some areas where you bleached may look better as galaxies, and some may be better suited to being nebulae, stars, super novae, etc. Use your creative judgement on this one.
To paint your galaxies and nebula, you want to start off with a dark color, such as a red or a purple and lightly dab against your fabric using a sponge. I used a cheap black craft sponge which I don't think gave me very good results. I suggest using a natural sponge for a more even texture. Then go over this which gradually lighter colors. Once you have the background to your galaxies and nebulae finished, you should paint in the stars and other bright objects in last, using lighter and brighter colors.
(finished back of shirt)

This should approximately be your finished project! Once this step is done, feel free to do whatever you want with it. Personally, I added studs to my shirt and ripped the edges of the sleeves and neck line. But as long as your object of choice is dark colored and bleachable, you can use whatever you'd like. Though if you plan on using yardage to create an item, I suggest painting the fabric before sewing it, just so you have more control over what patterns go where.
Happy crafting!