We are going to selectively sun-bleach a design on a shirt.
The advantages of using this method over others are mostly not adding another material to our shirt (e.g. a layer of paint) which will then change the feel of the fabric, and not messing around with chemicals which a. cost us money, and b. are harmful to us and the environment.
This method is safe, it's easy, it's cheap (absolutely free if you have a black t-shirt and a knife) and reasonably accurate - although this last one is mainly up to you.
The main disadvantage to this method is that you can really one "print" in one color, and it's just a brighter version of the color you now have. I had a black shirt, and the print came out mid-grey. I'm thinking that you can probably dye your shirt a different color after you bleach it, but I have yet to try.
Interested? Follow along...
Step 1: What will you need?
First you're going to need cardboard. I used the corrugated kind (not sure of the name - it's a three layer affair with the middle one wavy), but you can use any kind. For the backing I'd suggest a stronger kind for support, but the front can probably be a heavy duty paper as well.
You're going to need two pieces that will at least cover the shirt completely.
A good knife. I used the knife shown in the pictures, but a good exact-o knife or scalpel will work as well.
Double sided tape.
Some form of clear sheet - you will see why you need it if your design has "islands".
And that's it. Oh...
A shirt. Darker colors work best, and I'm not sure - but I think you need it to be cotton.
I also used some miscellaneous items to fasten the two pieces of cardboard together, and some staples to hold the shirt in place... Just use whatever you can find.
Step 2: Laying out your design
Keeping in mind that cutting a thick cardboard stock might be difficult and that the first trial may not be as accurate, I chose a simple geometric form - an alien from 'Space Invaders'. It also served an other purpose - it's easy to plot without a printer.
If you chose to use thinner stock or have access to a laser cutter, feel free to use a more intricate design, but just know that folds in the fabric and light leaks are a probability - making thin lines and shapes invisible or distorted on the final outcome.
Plot your design on the cardboard around where you want it to appear on the shirt, and proceed to cut it out.
Step 3: Cut it out!
Carefully, and on a cutting mat if available, cut out your design.
If, like mine, your design contains 'Islands'*, don't worry - cut the outline of the shape completely, cut out the islands, and save them for the next step.
*Islands - in my example, those were the eyes of the alien (notes on Pic. 3). Two pieces (islands) that were supposed to remain, completely surrounded with a shape that's supposed to be cut away.
Step 4: Dealing with islands
If your design is 'smart', it has no islands. But what if it does?
You may find a better solution - but mine was using a clear acetate sheet as backing, and then pasting the islands back in.
Use double sided tape to secure a flat, clean sheet of clear acetate to your design, and then place and glue (using more double sided tape) the islands in where they belong.
If you saved the shape you originally cut out of your design, placing the islands in the exact position should be a breeze - place the cut out back in the hole it was cut out of, put some double sided tape on your remaining pieces and place them where they belong. then, just remove the shape back again, and there you go.
P.S.: I just eyeballed it.
Step 5: Closing it up
First, you need to secure the shirt to the back piece. My advice is to cut a piece of cardboard just large enough to fit the shirt and putting it inside. This will ensure a flat and stretched fabric, and will also be easy to secure.
Using whatever you can find, stretch the shirt and secure it to the backing - I used a combination of staples, thumb tacks, double sided tape and a few curse words.
Then, I used some office binders and clamps to secure the front side with the design to the backing, making sure that the shirt was flat, stretched, and at the right position. I also made sure to tuck away any loose fabric - any piece of fabric that is exposed will get sun-bleached.
Step 6: Hang it out
Find a nice sunny location, and point your design to the approximate south for maximum exposure (might work differently for you of the southern hemisphere). Hang it or place it securely, and out of the way of dogs, children etc.
It stays there for as long as you wish. I found that at least a couple of days are needed for a discernable change in color, but the shirt should really be exposed for more - a week for a dark-ish grey, more if you want it lighter.
This all depends on the sun in your area and the dye used for the shirt, so your millage may vary.