View Full Version : acrylics + cornstarch ?!?

03-28-2002, 06:27 PM
out of curiosity, has anyone tried mixing acrylics and cornstarch, or a sth like it? recently made a small batch cornstarched acrylics (with a little water to loosen the starch) and applied to i-forgot-what-type-of-med-weight paper, but i dunno if it'll last. if anything, it does thicken, "cream" the acrylics. any theories?

03-29-2002, 04:06 PM
Yes. The paint layer was of a "normal" thickness 1/32-1/8 of an inch on canvas. Didn't cake it on for the sake of lamination.

It mircro-cracked when it dried and I varnished it about a week later. It was a nice effect. That was about two years ago and the painting is still in new condition.

03-29-2002, 10:11 PM
Thanks for the assurance, espax ... I wasn't too sure about throwing anything or everything I can get hold of onto paper, but I guess it's too late now, lol. I decided maybe the only way to find out was to try it out meself, so I brushed some on, and it seemed to dry even quicker than regular acrylics, or maybe it was just me?

I'd also extracted a small batch of the stuff, dumped salt, sugar and honey to it, and the result was quite gloppy, but very fresh ... maintained this glossy look as if it was still wet. I don't think the salt and sugar did anything, but the honey surprisingly thinned it out. The stuff's got some neat variations to the texture, depending on how you apply it. Smells nice, too. ;)

Your method's is quite interesting ... a sort of a paint crack effect? Wonder how far, and how to control the cracking. Blow dry?

03-30-2002, 06:38 PM
This one's a cheers to espax, hehe ... inspired by the crack and varnish effect suggested to me - well, not exactly, but the texture's not bad at all. Sorrie for the bad photos ... the gloss varnish didn't help with that ...


and a closeup ...


all comments and questions welcome.

03-31-2002, 12:39 PM
Hlee, I have never heard of this before but I guess there are tons of ways of doing something. The only thing that kinda concerns me is that I know when I make up concoctions for the kids, it has to be stored in the fridge and in a certain period of time for mold will start to grow. I dont know if this would apply here.....

03-31-2002, 01:03 PM
Yeah, Caron, I dunno either - that was one those creepy thoughts I had too, even though I was already semi-possessed at the time.

Thing is, you have to mix water to get the cornstarch acting, or ..... hmmm, does it make much of a difference if you add sth else, like oil, or ... because acrylic binds to just about anything, maybe, and this is silly, the synthetic plastic whatchamacallits it's composed of might prevent any mold from growing in it by absorbing moisture or isolating cornstarch molecules from it?!?

To be doubly sure, I think the varnish would do it good - seals it off from the atmosphere, so that if anything's growing, at least it can't climb out and strangle anyone, lol.

03-31-2002, 01:08 PM
I dont varnish my works either so I dont know alot about them to know exactly how the varnish is made up for acrylic paintings. But I do know that watersoluble varnishes(that you use on woods) does allow the air beneath. Still allowing a reaction to occur unless of course as you say, the components of the paints stops it..Interesting..but Im no chemist..:)

04-01-2002, 12:45 AM
Me, neither. :D But I'll see how it goes ... espax seems pretty confident it won't "mold" ... and I'll monitor my artwork too ... tell you any changes for the better or worse pronto.

Ah, the alchemy in artmaking ... :D

04-01-2002, 03:17 AM
This sounds like a neat idea but I wonder...wouldn't bugs begin to eat the pain/cornstarch mix after awhile? There are some bugs that will eat just about anything slightly organic.

04-01-2002, 01:14 PM
Wow...that sounds like a neat effect...I would like to try that! I am guessing that one would have to varnish immediately due to possible deterioration in the long term ...but what varnish to use???

neat work Hlee!! :D

04-01-2002, 05:28 PM
Thanks, paintergirl ... I didn't exactly used varnish, but an outdoor gloss sealer ... made to last, lol.

O Kitaye, don't think I'm not nervous about it! I can still conjure up the image in my mind of what happened the last time chemical cornstarch and chemical oil or water mixed ... :crying: but so far, nothing, er, unexpectedly unpleasant's happening.

The red was the acrylic and cornstarch, but I also added gave it a little rub with a stick of willow charcoal before I sealed it off with that varnish. Maybe that'll help too? Haven't heard of any mold that likes eating charcoal yet. :D

04-01-2002, 05:35 PM
I shouldn't think that bugs would get to it if the canvas is properly gessoed and then varnish is aplied once dry.

Oil paints are slightly organic and i have never heard of anything eating it....

Ah, and that cornstarch mixture seems interesting. You could probably use it to make relief of your painting and add some interesting texture if you wanted too....

04-01-2002, 06:12 PM
OK, so all portents point to a good painting, so that's good - bugs not extra interested in paints, I mean.

Hum, a thoughtful suggestion, Bendaini ... guess I could give that a shot too ... load more of the paint on it ... and it'll be relatively easier to get highly variated textures, too, seeing acrylicornstarch's thicker and dries quicker, methinks, than acrylics.

04-01-2002, 07:15 PM
When I did the painting, I don't think I mixed it with water first.

As a rule, I add water to the palette only with an atomizer. So I assume that is how I did it then (I cannot remember) that is, sprinkle the powder in the paint on the palette and then a few squirts of water to make it workable.

I definitely did not make a paste first and mix it into the paint. If that's your method, I don't know how long it will keep.

The climate where I did the work rarely drops beneath 70% in the summer and it dried without incident. Keep in mind that I used a thin layer of paint, no more than an eighth of an inch. I will try to shoot the painting this week and post a photo of the effect.

04-01-2002, 11:11 PM
Oh no, espax ... I dare not make the paste first, lol ... I thought I'd mix a small beta batch ... threw 2-3 tbsps of acrylic, 2-3 tsps of cornstarch then a little water at random into a lil' yogurt pot.

If I'd made the paste first, I'd have to add way more acrylics to even it out ... and since I was working in acrylics after all, it was natural I added the weird stuff to it, and not the other way around.

But you've raised a good question, though. Does it make a difference to the permanence of the stuff, whether it's cornstarch and water to acrylic or acrylic to paste? :confused:

Post a painting? O yeah, please do ... I'll love to see how you'd used acrylicornstarch ... lots of unexplored possibilities, even if it's risky in a sense.

04-02-2002, 12:08 PM
While I haven't done it, I'd venture to guess that over if you add more than 20-25% powder by volume, you will have lamination problems with the paint. When coupled with the water/medium, you don't have as high of a concentration of binder in the paint.

Now if you made your medium a heavy gel or molding paste instead of adding water, you could probably support more powder.

04-02-2002, 11:43 PM
Originally posted by espax
While I haven't done it, I'd venture to guess that over if you add more than 20-25% powder by volume, you will have lamination problems with the paint. When coupled with the water/medium, you don't have as high of a concentration of binder in the paint.

Yeah, I think you're right ... there'll be less binder, but if you don't overdo it, it won't be that obvious, I hope. Guess the advantage's the thickness of it, for texture ...

Now if you made your medium a heavy gel or molding paste instead of adding water, you could probably support more powder.

Do you mean instead of adding water to the cornstarch and acrylic, to use medium? Would there be enough moisture to activate the starch? ... I'll give that a shot, too, thanks ... :)

04-03-2002, 12:51 PM
I'd say adding the starch to something like molding/modeling paste (liquitex makes on that I like) and then misting it with a little bit of water would make it all come together.

Enjoy the experiment!

04-03-2002, 06:33 PM
Yep, experiments are fun - when they don't blow up on you!

I had some problems with honeyed batch ... I used it for another of my letter-number series and kept forgetting it wasn't completely "dry" ... and got at least two other pieces with the stuff gunked on the back! :mad:

I got most of it out ... the stuff took ages to dry, but the end result was worth it. Funny effect, or could've been due to incompletely dissolved salt/sugar ... bumpy with little white "bubbles" ... I'll get a shot of it and post it here asap.

04-04-2002, 12:46 PM
As you can see in the grooves, the powder was mixed in with an ground color for that area and placed with an old butter knife, hence the combing effect. Then the paint was worked in, and so the combing isn't uniform. You can see a more uniform effect in the pic in the next post.

I think it only took a few days for the craquelure to form, maybe less. I did give it a full week to dry before varnishing (overkill).

cornstarch closeup one:

04-04-2002, 12:47 PM
closeup two:

04-04-2002, 06:20 PM
Well aparently this didn't work. I meant liquid corn starch in case you were following my suggestion.


04-04-2002, 06:22 PM
Giving it a week to dry puts you on the safe side ... I just learned that it could take months for acrylic to dry completely, depending on how thick the layered paint is!

There's some neat things going on with the two closeups ... though I rather like the first one, since you could see the cracks and "scrapes" more clearly. Ah, but the other one's more subtle ...

Vallarta - may I ask how you prepared the acrylics and cornstarch? What did you mean by liquid cornstarch? No really, your method's fascinating even if it didn't work ... did you get the cornstarch in a sort of paste or very runny form first, before adding it to the acrylic?

04-09-2002, 01:37 PM
Many years ago I used a chemical product processed from the inner layer of tree bark. Let's call this product CMC. It was used as a paint thickener. It had some other really amazing properties,too. This probably would not be alot different from cornstarch. My latest information on this product is not so good. In the good old American business tradition, the sale of CMC is controlled by a big chemical company in a monopoly arrangement. They will sell the product to paint manufacturers only. One of my back burner projects was to try to find some powdered vegetable protein at a health food store and do some experiments with acrylic paint. I still may try it some day. btw, the complete name for the material is sodium carboxymethylcellulose.

04-21-2002, 04:02 PM
Just wanted to coment on this subject, I did do a number of pieces mixing tide with oil paint for an interesting texture, I do not know how long they will last but it sure came out with the most interesting texture even different than sand which I have used many times...