Unfortunately icons as PNG are not supported by WireframeSketcher. Do you need some specific icon that you can't find in the standard library? Do you know that you can also install extension packs with additional icons from our website (see "Stencils")?
André20 Jan 2017
Thanks for your answer.
Yes I need special icons. We are using WireframSektcher to develop mockups for computer and not for web. Our customers need sometimes a few special icons. And so we are using icons from axials. I prever to make the decision about a icon as soon as possible. Later in programming we have no time to discuss the icons again.
Have a look at axialis and you see, this icons are sometimes for specials.