Coloring books have strong, single line patterns that can be enlarged to create yard art patterns. Shop garage sales or thrift stores for other types of books that may reveal silhouettes or stencil patterns. Clip art can provide many pattern ideas. Simple outlines can be filled in with details to define the image. Stay away from intricate patterns, because these may be difficult to cut out. Intricate details can be added back using paint---use the original image for inspiration and information.
Don't limit the search to books alone; include textiles and printed fabrics. Designs from birthday cards, wrapping paper and posters can inspire yard art patterns, too. Images can be enlarged directly on a copy machine or via a computer scanner. Test an idea by tracing with a black marker over the image using tracing paper found at arts and craft stores. Create duplicates of the outlined image and experiment with how the image would be painted by trying out color palettes and painting styles on separate copies.
Create vignettes or still-life assemblages that mimic the desired results using such items as dolls, action figures, cars, kites, watering cans, baskets, landscape edging, trellises and wheelbarrows. Snap a photograph of the item or vignette for an artist to work from or hire an artist to draw directly from it. The result should be an outlined shape of each single item or an overall shape that will be cut out of plywood and painted.