Oil Painting!

Another food colouring post! (Hey, I have so many bottles, gotta find some way to use them up….)

Porthos asked to make volcanoes the other day. We didn’t have sodium bicarbonate on hand, so on the spur of the moment, I suggested something different. We know that every time we use food colouring with water or vinegar, the solution completely changes colour. I asked Porthos what would happen with oil and he assumed the same thing would happen.

“Let’s see” I said.

So we poured some oil onto a dish

oil-and-colour-1.jpg

Then we put in a few drops of food colouring

 

oil-and-colour-2.jpg

And even when we agitated the mixture with a chopstick, and added some more colouring, the stuff just wouldn’t mix. Instead. we had some really funky oily art going.

oil-and-colour-3.jpg

If you want to get into the science, the essential point is that food colouring is water-soluble, but does not dissolve in oil.

 

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2 responses to “Oil Painting!

  1. When I was a kid we used to drop a few drops of thick, liquid, water soluble poster paint onto a tray of water using a straw, give them a gentle swirl and then gently lay a sheet of paper on the surface and lift it off.

    It would produce a marbled effect, like the inside covers of old books.

    The way we used the straw was to just dip it in the paint and then hold it a couple of inches above the tray and give the straw a gentle tap.

    We’d use a few colours to get a nice mix.

    ๐Ÿ™‚
    David

  2. David, what a great idea! We’ll give it a try so look out for the post ๐Ÿ™‚

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