Using Derivan Cracking Medium


I love painting rusty old things and creating an aged effect with paint on canvas. In this blog I am going to share the techniques used in the acrylic painting on the right, “Hanging About”. If you look closely you will see a little fly in the picture. I took the photo of this green tree frog in the Kimberley many years ago. I was looking through my photos and saw this and thought he would be perfect on on this background that was inspired by the Brighton Bathing boxes. The fly was added to add some interest and humor to the work. The painting looks like wood but is actually on canvas.

Scroll down to see the  step by step photographs of how this was created along with written instructions.  At the bottom of this post I will put a link to my Youtube video of the cracking and distressing process.


green tree frog catching fly

First I painted a dark background. This is going to be the colour that shows through the cracks so it needs to be a contrasting colour. Then I thickly applied the Cracking Medium where I want the cracks to appear leaving the area where the frog will be blank. The cracks will follow your brush work so apply the Cracking Medium with this in mind.

Once the Cracking Medium is touch dry your ready to paint over it. I have found that the longer you leave this the smaller the cracks will be. A more liquid paint will crack easier than a paint with more binder so I use the Matisse Flow paint for the top coat mixed with a few tablespoons of Matt Medium. This helps the cracking along.

Now paint the top coat. Use long strokes in the direction you want the cracks to appear in. Do not go back over your brush strokes as it will prevent the paint cracking. The cracks will start to appear within minutes and continue to develop the entire time the paint is drying. More Cracking Medium and a thicker top coat creates bigger cracks.

Here you can clearly see the area I left untreated for the frog. It does not have any cracks. Notice how the cracks are vertical on the left of the blue tape and horizontal on the right. I have deliberately altered the direction of the cracks to follow the grain of the wood I am creating. The blue tape is going to be used to help me paint a line.

I have squeezed out a generous portion of Cobalt Teal and Aqua Light Green side by side on my palette and here I am lightly dipping the brush into the paint so it is “double loaded“. This technique means you have more than one colour on your brush.

Starting from the tape I lightly brush over the cracked white paint to create a distressed look. Notice how the “double loaded” brush creates more interest by combining the two colours.

Next peel off the tape. Notice the beautiful clean line created by the masking tape. I am using the Blue tape for sensitive surfaces.

Now I sand back a bit of the paint just to further distress some areas. I must confess I got bored with the hand sanding and used an electric sander in the end. The ‘nail holes’ are actually created by running the sander over the canvas with my knuckles underneath.

Painting the nail holes

You can see here how I have brushed a little Deep Rose Madder and Australian Sienna out from the nail holes to look like rust.

Painting a straight line

Next step is to add in some shadows to define the planks of wood.

Frog outline

Using a chalk pencil I drew in the frog and then under painted him in white Gesso. This gives me a solid flat surface to paint the frog on as the paints are slightly transparent.

Painting the frog

Finally I paint the frog tonally using my various green shades and when this is dry I add the finishing details over the top. I added the blowfly last. It’s the little details that add intrigue.

Pin It on Pinterest