The nautical charts used in my prints are all downloaded from various sources. I try to use older charts when I can to keep a rustic look to the final print.
I use various charts specific to different coastal areas of the United States coastline. I digitally import my artwork onto the charts by using Photoshop. I then manipulate different paintings of mine to fit each of the chart areas I offer. I also offer different colored backgrounds of the charts using various filters.