I got paint on a favorite T doing earth day activities with my kindergarteners! I’ve tried all my tricks but it still shows. It was just tempera!
Paint is generally difficult to remove from fabric, but it’s not necessarily impossible. The sooner you can get to the stain and rinse it before pretreating and washing the better. Keeping it out of a hot dryer while you work on it is also important. And of course the type of tempera paint makes a difference. According to the staff at my local art supply store (that serves our local art college) there is a wide range in the quality of different tempera paints. Tempera contains colorant in pigment form, which doesn’t dissolve in water. It also contains a binder of some sort to help the colorant adhere to the paper (or whatever medium is being painted). Higher quality paints have a heavy pigment load (so more concentrated) and stronger, more effective binders to better approximate the appearance of oil based paints and acrylics. Tempera that is actually labeled as washable should have a much lower pigment concentration, and, since it is water-based, should be easier to wash away. But here’s something else interesting that I learned: according to the art store staff, while even their higher quality tempera is technically considered washable, the color also makes a difference, with red shades nearly impossible to wash out. So I wonder what quality of paint you were working with, and what color.
Something labeled for children’s use and described as “washable” should be removable if you pretreat it with a little liquid laundry detergent before washing. It would also be helpful if it doesn’t dry out on the fabric before you start to work on it.
Since what you have already tried has not been successful, then you may be working with a higher quality of paint, or red paint, or maybe it dried out before you started working on it. If the stain has lightened considerably but is still visible, and is on a white, bleach-safe item (always avoid bleaching wool, silk, mohair, leather, and spandex) you could try pretreating with Clorox® Bleach Pen Gel before washing with detergent and ½ cup Clorox® Regular Bleach2. The gel pen product contains the same sodium hypochlorite bleach active as our regular bleach, but at a lower level that is safe to apply directly to a garment immediately before washing, so you get concentrated cleaning power right where you need it. Note that our regular bleach should always be diluted before use, so don’t be tempted to apply a little full-strength bleach directly to the stain!
A lot is dependent here on the quality of your paint. If it is labeled for children and washable, your chances of success are improved. But if it is has a higher pigment load and a high quality binder, then even using bleach may not be effective for the simple reason that pigments don’t dissolve in water. Pigments, when properly used to dye textiles, are actually colorfast to bleach. This may or may not be what’s happened to your shirt, so there’s a chance that using the Clorox® Bleach Pen Gel before washing with detergent and bleach will work. I really hope it does so you can save your favorite shirt! But the fact that your stain is insoluble pigment makes this quite a challenge.
I wish I had more promising advice– good luck, and let me know how it turns out!