This paper introduces an automatic algorithm for nesting of irregularly shaped parts whose geometries were approximated by composites of non-overlapping rectangles. A performance test using randomly generated bills-of-materials (BOM) shows that the algorithm is efficient in terms of speed and material usage. This algorithm is then used to study the relationship between BOM characteristics and material trim loss. An experiment using a 25factorial design is used to estimate the impact that the total number of parts, the number of unique part types, the part sizes (in relation to material sheet size) and the percentage of irregular parts in the BOM all will have on the material trim loss in the nesting process.