This 6″ x 10″ piecing ruler has colored lines and markings which makes it wonderfully simple to make a combination of curved blocks which are used repeatedly in WCR Patterns! These unique lines and markings make using the Wonder Curve Ruler easy as, 1-2-3! The three bold colored lines also make it easy to scale a block larger or smaller just by aligning fabric with the different colors and marks. Cool WCR feature. The Wonder Curve Ruler can used for patterns: Happy Together, Cool Cars, and Plant Life. Included with the Wonder Curve Ruler is the pattern Wonder Flutters.