Potato Dextrin Resist

My fabric-dyeing group had a Water Resist swap this month and I decided I’d try using the potato dextrin that I’d had sitting around for about a year. This is one of those projects that you think to yourself “That looks cool, I’ll give it a go” and you order the stuff but then you keep procrastinating doing it because it looks complicated and time consuming. Of course the reality is that just like other things you put off doing, once you start it’s not hard at all.

The first step is to pre-soak your piece of fabric. I had a piece of ecru that I didn’t care for but always thought would look good with some black added to it so this is the piece I used. I let the material dry and then made up the dextrin. I looked up the instructions on ProChem where I bought the dextrin. I found it somewhat disturbing to find out that I’d need the whole bag for 1 yard of cloth. Call me a tightwad but at over $5.00 a bag all of a sudden the price of my homemade fabric shot up.

I didn’t have space to lay out the whole one yard piece so I divided it into two pieces. This turned out to be a good move on my part as after practising on the first piece I was better at the second. I taped a piece of plastic down to the table and then taped the fabric to the plastic and spread half of the dextrin over the material and let it dry.

Dried potato dextrin.

I guess the idea behind taping the fabric (aside from making it easier to spread the dextrin) is to keep it taut while it dries, it didn’t work as the plastic pulled away from the table and buckled. This happened both times so I don’t know the answer.

Anyhow next I made up some print paste from a recipe that ProChem has on their site. I did this because I wanted to slow down the rate at which the dye crept into the cracks. I’d heard from others that if the dye is too liquid then it just seeps under the resist and you get yuck results. The print paste was very thick and I was worried it was too thick but by the time I added the dye solution it thinned out. It was kind of interesting because I kept adding more and more dye and every time I stirred the dye stock into the print paste at first it’d be runny and then thicken up but by the time I reached the end of the dye stock it was of a good spreading consistency.

Thickened dye made with print stock paste.

Next I applied the dye into the cracks with a foam brush.

Material with dye applied over top of the potato dextrin.

I covered the top of the material with plastic and let it batch for 24 hours and then did the washout. In some areas the potato dextrin worked but in others I had applied it to thin and the dye absorbed through the resist and instead of a crackle I got a more solid looking area.

Finished material.

I wasn’t pleased with the fabric because it didn’t turn out the way I was expecting. It’s very washed out and how I got some darker tan spots in there I’m not too sure. The dye was blacker along the edges where there was no resist so it made me wonder if the resist was interfering with the action of the soda ash (you can see some darker dye just at the bottom edge of the photo). In Ann Johnston’s book “Color by Design” she recommends adding the soda ash to the potato dextrin when you’re cooking it up, unfortunately I followed the ProChem website recipe.

For my second piece of cloth I decided to add soda ash to the print paste/dye mixture as I’d already cooked the dextrin. The results were much better – darker so it does make a difference. On this piece I also tried to apply the potato dextrin in a thicker layer. Unfortunately I ran out of the dextrin so on the one end the dye is darker because the resist is thinner. The thinner the resist the finer the crackles and they are closer together as well so overall the fabric looks darker. I made up a paste of flour and water and applied that to the rest of the fabric.

I’d either made the paste to thick or didn’t spread it thin enough because it was very hard to break it up into cracks and I found when I applied the dye that the dye didn’t seep down through the cracks but some did so it’s interesting. I might had gotten better results if the whole piece of fabric was flour/water because it was difficult to manipulate the fabric to get the cracks because the potato dextrin resist was a finer resist and it was easier for it to flake off when I moved the fabric.

Potato dextrin resist on left with flour/water resist on right.

Larger overall photo.

Potato dextrin resist.

Flour resist.

I’m pleased that the second piece of resist worked out. If I had a cheaper supply of potato dextrin then I’d try another couple of pieces but given how much I pay for importing fabric and dextrin it works out to about $12/yard and I can buy ready made fabric cheaper than that. I think I’ll try this again but with a cornstarch resist and see how that works out, it’d be less costly.


5 responses to “Potato Dextrin Resist

  1. I really love your results – I hope you are able to find a more affordable substitute. I have some dextrin, will have to dust it off and try it!

  2. me too! I think you’ve presented me with a solution to an issue I’ve been pondering for quite a while, thankyou 🙂

  3. omg so beautiful
    ilove it
    thanks for share ❤

  4. Instead of taping the fabric, pin (quilt pins), the edges around the fabric — use a styrofoam base (styro- insulation board). I too prefer to add soda ash to the print paste, but if you don’t use it all, the dye will not keep. The fiber and weave structure of the fabric will affect the outcome. Also, the temperature of the print paste when it is applied, as well as the temperature and humidity of the room it is drying in. Those factors, and more, combined with the thickness of the spread, will all affect the outcome. Hope that helps!

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