Roberta asked what I use for my block printing material. I like Innovart Eco Printing Block material, which is available from Dick Blick. Here is the link to the page for the printing block material I use. It is affordable, 100% recycled, and holds up well to a lot of use.
I now have six different blocks with Starry Night swirls. I think it is more interesting with the mix of sizes.
I have used two different colors of blue Setacolor Transparent paints for the printing; Ultramarine Blue and Cobalt. I like the way the yellow screen printing peeks through and kind of twinkles.