Display "Add to cart" when no price is used

My store will be used for clients to select images to be used in printing. Each image will be a product, and none of the products will have prices. However, without adding a price, I cannot seem to get the "Add to Cart" button to show.

Is there a way around this?

Yes. You can activate the option "Display 'add to cart' button for free products" in the config under the tab display (you might to update as it has been added recently).

Excellent!!! Didn't see that!