Unless the painting paper has plastic or tape, in Other words, is not all paper with no coating etc, to stop it from rotting, I would use either. Newspaper, (non-glossy) is great too, and free, if you go where they dump it off to recyle, or you get a paper anyway. The newspaper is a bit more work if you get some breezes, or lots of wind that day when you try to use it. I have used it to expand beds, just put down a heap of mulch to hold corners down while using and when done cover all the paper with mulch or soil, whatever you want to use for your plan. That's my 2 cents anyway. I use about 6 pages thickness for each joining piece coverage.

Thanks for this! I've posted it on my F'book page.

I was looking in a drawer just this morning and found some of the tak stuff. Good idea.

I agree, you don't need to use parchment.... But my concern is what kind of "decorative dish" will you be using? You need to be concerned about the size...area...of the pan you're using and make sure it's pretty close to 204 square inches, too small and the filling will be too thick and may not get done before the edges get too brown. Sounds good...you could bake the recipe in 4 8 inch round pie pans and it would ba about the same area as a 12 by 17 pan.