Does vinegar help set tie-dye? No, vinegar will not help to set fiber-reactive dye on cotton fabric. Nor will not make the dye more resistant to fading. Contrary to popular belief, you do not need vinegar to set tie-dye on cotton.

Should I set tie-dye with vinegar?

Try soaking your tie dye in equal parts white vinegar and cold water for 30 minutes after you initially rinse out the dye from your garment. The vinegar helps with colorfastness. After the first couple of washes, wash tie dye in cold water to prevent dye from fading.

How does vinegar affect tie-dye?

In fact, when we are trying to tie-dye a shirt we actually use something called soda ash which is alkaline. Vinegar is acidic which is the contrary of what we need. For the dye to work with cotton we need to create a basic (alkaline) environment and vinegar would ruin that.