Alison: Here I am picturing a series of pages - one per series or gallery or whatever we decide to call them - a set of related paintings. For EACH page I am picturing a layout like what you see below.
Below THAT, you can see my mockup of what it will look like when someone clicks one of the paintings - ALTERNATIVELY - when they click a painting it will open a new page just for that painting.
Food for thought.
up there ^ is what it will look like as a gallery
optionally, below is what it will look like when clicked - see note above.