It's a good thing Pencil is simple to use, because it's undocumented. Its website does contain a wiki, but it's for stencil developers, not end-users. The company was hard to reach for press inquiries and did not answer our questions about system requirements. To use Stencil, you just need to play around with it until you can make it work. The interface is straightforward, but not without its share of surprises. For example, you can't draw a selection marquee to select multiple elements: The only way to select several elements is to Ctrl-click each.
While Pencil isn't perfect, its attractive price tag and comprehensive glyph sets make it a solid option for getting started with interface design and sharing your vision for a new website or mobile app.
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