Learn how to prep fabric for tie dye using soda ash. Discover the difference between soaking and sprinkling for vibrant, long-lasting results.
If you want bold, long-lasting color in your tie-dye projects, how you prep your fabric is everything. And the secret sauce? Soda ash. In this post, I’ll walk you through exactly how to prep fabric for tie dye, including two different methods—soaking and sprinkling—and explain why it matters so much. If you’re new to tie dye, you might also love my Tie Dye FAQs and this deep dive comparing the best tie dye brands for bold color.
One of the most common questions I get is ‘how do you get your color to stay’? The first and most important tip I have is to make sure you have the right fiber content, but after that, using dye that requires soda ash (procion) is, in my professional opinion, the only way to really get tie dye color that lasts forever.
Before you start, make sure you have the right supplies! I put together a full guide to the Best Tie-Dye Supplies I use for every project — check it out here.
Why Soda Ash Matters
Soda ash (sodium carbonate) raises the pH of your fabric, which helps fiber-reactive dyes (like Dharma Trading or Procion MX dyes) bond to the fibers. Without soda ash, your colors will likely end up pale and will continue to fade over time. You can get soda ash from Dharma, Amazon, or even the pool aisle at Walmart. Many of my top picks in the best tie dye kits on Amazon include soda ash, so you’ll be all set.
Method 1: Soaking Your Fabric in Soda Ash
Soaking is the most effective and reliable method for prepping fabric. Here’s how to do it:
You’ll need:
- Soda ash
- Warm water
- A tub or bucket
- Protective gloves
Step-by-step:
- Mix 1 cup of soda ash into 1 gallon of warm water.
- Soak your fabric in the solution for at least 20 minutes.
- Wring it out so it’s damp but not dripping. (Some people use a wash spin or a Panda spinner, I just hang dry a bit if needed.)
- Proceed to fold and dye as usual. Once your fabric is prepped, try out one of my favorite Shibori folds for stunning patterns.
Pros:
- Deep, vibrant colors
- Better dye-to-fabric bonding
- More predictable results
Cons:
- Takes extra time
- Requires more setup/clean-up
Method 2: Sprinkling Soda Ash on Top
Short on time? You can sprinkle soda ash directly on top of your project after you apply dye, especially in ice dyeing. If you are planning to only use your dyes for ice dyeing, I’d even suggest mixing soda ash in with your powdered dye.
What to do:
- Tie and set up your fabric
- Apply ice and dye
- Sprinkle soda ash powder evenly on top (or add it into your dye first for ice dye only)
What I’ve found:
- Colors are still bright, but often a little more uneven or splotchy
- Works best for ice dye projects
- Can cause speckling or inconsistent saturation
Soda Ash vs No Soda Ash: Real-Life Test
In this video, I compared two tea towels dyed side-by-side—one soaked in soda ash, the other just wet with water. The difference? Wild. The towel with soda ash held vibrant color, while the one without it lost dye fast during rinse-out.
I did another experiment comparing soda ash soaking vs sprinkling. The soaked towel came out more saturated and smooth, while the sprinkled one had more speckles and uneven patches.
So… Do You Have to Use Soda Ash?
If you’re using kits like Tulip or Rit, soda ash isn’t needed. But if you want professional-quality results that won’t fade in the wash, soda ash and procion dyeing is the way to go. Next up, learn exactly how long to let tie dye sit for the best color, and see my full rinse + wash guide to keep it bright wash after wash.
Final Thoughts
If you’re wondering how to prep fabric for tie dye, soda ash soaking is your best bet. Sprinkling can work in a pinch, especially for ice dyeing, but soaking gives the most reliable and bold results. Got questions about soda ash or your next dye project? Drop them in the comments or DM me on Instagram @storebrandanna.
