Heat setting is the last step for a lot of fabric inks, including the ones I used for stamping (Speedball Fabric Screen Printing Ink). The heat bonds the ink permanently to the fabric, so you can wash it and your design won’t come off.
So, how to do it. The most foolproof method is what the manufacturer recommends: ironing.
After the fabric ink dries on the fabric, set a household iron at the highest dry heat (no steam) that will not scorch the fabric and with a cloth or paper between the iron and printed material, iron on each side for 3 – 5 minutes. This will make the ink withstand repeated washings.
The first time that I did screen printing and stamping, I decided to look for alternatives, since I wasn’t too excited about ironing each part of the skirt I had stamped as directed above. I emailed the company to ask about other methods, and just how hot the ink needs to get. I got a helpful answer back, including the answer, 350-375° F, and the suggestion that I could try heating my items in the oven.
My oven set method: Preheat your oven to 400 with an extra metal pan inside to pour water into. Boil some water. Fold your printed piece and wrap in scrap cloth or place inside an old T-shirt, so that any scorching or oven gunk goes on that and not your creation. You can also put old fabric or paper between items if you are worried about transfer of ink. Don’t make your fabric bundle so dense that it will take too long for heat to reach all of it. Place your bundle on a cookie sheet. When the oven gets up to temperature, turn it off. Open the door and pour a cup or two of boiling water into the extra pan. Quickly pop in your cookie sheet and shut the door again. Leave everything inside with the door shut for 10 minutes. If you have an oven thermometer and a window in your oven, you should be able to check that the temperature stays above 350° for at least a few minutes. Common sense note, this method will not work for synthetics (although I did a partly polyester apron and it seems fine) or anything that will melt at those temps. If you have a piece with meltable parts, like nylon bag handles, you will need to iron the design/printed part only.
I have had good success with this oven method, I did the skirt below this way, without a steam pan, and it has survived years of washing and wearing without any noticeable fading in the design whatsoever. In fact, I remember that I washed it before reading the manufacturer recommendation that you wait a week before washing the first time, and as I said it still looks great! Some other folks that I shared the oven method with (and even myself once, when I didn’t turn off the oven – not a good experiment) have had some problems with fabric scorching around the edges. I came up with adding the steam pan, since fabric can usually take practically any heat without scorching as long as the heat is wet. I heat set a big batch of dish towels this way with my friend Megan a couple years ago, I checked in with her and she said that those designs have held up to lots of use and washing as well.
A couple of things that didn’t work: as extra insurance against scorching I tried wetting the old towel that I wrapped my last piece in before putting it in the oven. Everything smelled like warm steamy fabric, but I don’t think it got hot enough inside. I have also heard that some people use a commercial dryer, so I snuck into the laundromat with a couple of samples from my latest stamping day with friends. I put all these test pieces though the wash 6 times, as I was doing laundry between then and now, and hung them on the line to dry. They all show significant fading and some of the motifs are totally gone. So for now my best suggestions are the ironing and oven methods above, I will of course post an update if I come up with a new and better way!
One more thing I’d like to talk about, and this seems as good a place as any, eco-friendly printing! Part of what I love about DIY is the ability to turn something you wouldn’t use into something you will, and save resources and cash. I hate it when I realize that I’m wasting supplies, or sending lots of extra stuff to the landfill when I’m crafting.
My tips for “green” fabric stamping are: for clean up, you only need a cup’s worth of water and an old toothbrush, and a rag. When your hands or tools get messy, rinse them in the water, then wipe them on the rag. Heat set the rag when you’re done to use again (it looks cool). Reuse paint mixing cups by pouring out excess paint (into the trash, or onto something else?) and letting them dry before putting them away. I use one plastic spoon to scoop paint for each primary color, and one to mix each new color. I let all the spoons dry at the end and save them for next time. The foam brushes I rinse in the clean-up cup, then a final time in the sink, and again let dry. If you use something that’s still useful with paint on it, like a mailing box, under your paint jars to protect the table, the total waste is down to a little unused paint!
Well, that’s about it for this project, please feel free to add comments if you try printing, how does it work for you? I’d love to hear more ideas for heat setting as well! Stay tuned for more DIY . . .