This is how the left corner of the painting looked when I stopped at the last post. I focused here so you could see the before and after.
I cut a mask using a heavy piece of plastic (the kind from boxes) and scissors. I cut around the large petal in the front of the flower. Then with a damp soft silk sponge, I gently lifted the colour from the petal, blotting with a dry kleenex before lifting up the plastic. I could have lifted all the way back to white if I wanted, without harming the paper, this way.
You can see that the front petal now stands out nicely in front of the back petals.
This time, I cut a mask from some 'watercolour washout tape' with an exacto knife. The tape is heavier than regular packing tape and has less stick so it is less likely to damage the paper when it is removed. Packing tape will work however, you just need to be a bit more careful with the knife not to score the paper. For some reason you can tell when you have gone through the washout tape and it doesn't damage the paper. I lifted with the soft sponge the same way.
"My Poppies", watercolour, 6.5 x 10.5"
This is the final painting. You can compare this with the end of the last post to see the results of the lifting. Because the paint is put on in a juicy way without rubbing the paint into the paper, it is easy to lift back. This lifting not only sets petals in better approximation to the others, the lifted petal takes on a velvety translucent texture, just what you want a petal to look like. I also lifted out the bud in the centre with a mask, and then put a light yellow-green wash over it. Voila, a bud that looks like it is behind the flower.