Thank you for the suggestions! I haven't had much time to practice (wouldn't you know, harvest is deemed more important around here
) but I tried again being very careful not to get too close to the lines when blending. It seemed to help a lot and I just had to go back over the edges a little when I was done so that there wouldn't be a line between the part of the darker color that got blended and the part that hadn't. Does that make sense?
I also want to try the paper towel trick if I have any further trouble.
Today's attempt is shown here: learning to use spectrum noir by happy-stamper - Cards and Paper Crafts at Splitcoaststampers
The image is about 1 1/2" and I used the large tip of the markers. I'm not happy with the blending on the bottom petal and I'm thinking that maybe I should have used the small tips for this size image....