After the success of finding the 3m waterproof masking tape and the problem of leakage when painting over earlier layers I spent some time thinking about this problem and playing with the paint. It was then I noticed how my watered down paint sat on top of the unprimed canvas as the picture on the left shows and it did not sink into the canvas until I actively forced it in with the brush. I then compared this to an area I had previously painted. When I placed the next layer of paint on the previously painted area I noticed that the canvas no longer repelled to watered down paint but absorbed it without and further action from myself.
Here was the reason to the problems I was having. For some reason the normally water repellent unprimed canvas seems to lose its water repellent qualities once it has received a layer of paint. This was why I was getting the seepage underneath the masking tape. Now that I had discovered exactly why I was having a problem I was a lot closer to finding a proper solution.
I now started thinking about how I could seal the canvas after I had laid down the first layer of paint. I wanted something that would effectively waterproof the previously painted layer as well as the where the masking tape sits on this painted layer. I decided to try using some rabbit skin glue as it use in painting is to effectively seal the fibres of the canvas from the harsh and destructive properties of oil paint.
Pictured left is the first canvas I was going to try the rabbit skin glue technique with. I melted some glue using the tradition jar inside a saucepan method. This was then applied to the long strip marked out with the masking tape strips. As rabbit skin glue is virtually the same colour as unprined canvas I took great care to ensure that all the area was covered fully with the glue as well as about have of the masking tape to effectively make a sealed section.
Once the glue had dried fully I appled a new layer of different coloured paint on top of the glued area. This time I left the masking tape on the canvas until such a time when the new layer had fully dried out.
When the masking tape was removed it came of in one long strip to reveal a perfectly clean line where the new paint layer sat on top of the area painted with rabbit skin glue. This was extremely satisfying as I had spent a large amount of time and money trying to get my technique working as professionally as I wanted it to. Now I was armed with a fool proof, 100% reliable process that I can hone even further and use as a basis for a new form of visual language.