Quote Originally Posted by JBrunner View Post
carbonate bleach/tannin tone [cyanotype] gets sun for about an hour every day. Going on two years now, and with no visible change...
I tacked one to the railing of the deck where it was exposed to weather for six weeks. It recieved sun from 11am to 6pm (when we have sun, this being Cleveland). No noticeable change - though I didn't keep a reference version. Seems they may last longer than RC prints...