Foundation piecing whether on lightweight fabric such as muslin or non-woven interfacing is generally the assembly of random sized scraps into a useful size such as string quilts or crazy quilts. On the other hand paper piecing generally involves very intricate patterns with lots of sharp points. Both the fabric and foundation are manipulated to produce the design. Small pieces of fabric are added one at a time, trimmed to straight shape (no curves) and then added to with other straight shapes. Various quilt artists have taken this concept to new heights-Judy Martin, Carol Doak and Judy Neimeyer. Designs can be quite simple or very intricate.