An ideal show tortoiseshell cavy has regular, well-defined patches of each colour on each side, and appears to have lengthwise seams on its back and belly.
Most models feature a black pickguard, though closer inspection reveals that some pickguards only appear black and are actually a very dark tortoiseshell pattern.
Some male calico or tortoiseshell cats may be chimeras, which result from the fusion in early development of two embryos with different color genotypes.