My swirl pattern turned out beautifully, but I did have trouble getting the image to transfer using the iron/hot plate. I think that this method reminded me of ironing clothes which I tend to do only when absolutely necessary. Getting my kids ready for school typically involves searching for those clothes with the minimal amount of wrinkles. Finding outfits that are coordinated is just a happy coincidence. So..........wanting to ditch the iron part of the process, I said that I had read (my incessant reading does sometimes yield valuable information, I think) about certain inks that are also resistants to ferric chloride. I came prepared with what I hoped was the proper ink and a variety of stamps.
The above piece of copper was first sanded with a very fine sandpaper which cleaned the surface and also created a subtle texture for binding the ink. I inked my stamp and carefully applied the image to my prepared piece of copper. I covered the back of the copper with packing tape and placed it in the container of ferric chloride. It took around 25 minutes to get the above result. I think it's beautiful, and I didn't have to iron!