I was told years and years ago that your dried watercolour paintings could have the same intensity that they did when wet if you applied a coat of Gum Arabic. It was only yesterday that I tried it for the first time on these samples. I hope that you can see that the left half of the little heart painting is deeper than the right. And, I painted a stripe in Gum Arabic down the middle of the second one. Quite effective!
Gum Arabic painted down the centre.
Gum Arabic painted on the left-hand side.