In addition to the Inhibitor gene (not present in the Golden series), a silver cat may also have the Wide Band gene The existence of a "Wide Band" gene is disputed. If it exists, Wide Band determines the width of the hair shaft colour (the undercoat) between the pigmented tip and the follicle. The undercoat length varies, being narrow on the cat's back and wider at the belly. It is believed that the presence or absence of the Inhibitor gene does not affect Wide Band since Golden Shadeds lack the Inhibitor gene, but have a shading pattern comparable to Silver Shaded cats. There may be polygenes which affect the undercoat width rather than a single Wideband gene; some ideas are mentioned in the section below.
Wide band is considered as either an effect (due to interacting genes) or as a gene. Leaving the exact mechanism aside, it can be treated as a dominant gene when looking at inheritance. If a non-agouti cat (self/solid cat) has dominant wide band (Wb), this will not show up unless it also has silver in which case it is a smoke. In tabbies, Wb may account for the different appearance of silver tabbies, shaded silvers and chinchillas (tipped). If a non-agouti cat has silver but has recessive wide-band (wb or narrow-band), it could account for the poor smokes and hidden smokes. Wide-band is noted to have an additive effect - one copy is wide band, 2 copies is even wider band. There may even be multiple alleles of wide-band.
While the Agouti gene permits the hairs to have bands of colour, separate genes for banding frequency, band width and band placement probably influence the banding pattern of the hairs. An ideal Shaded Silver hair would have a single broad band of pigment at the tip of each hair. Shaded Silvers have a mix of three patterns: a single broad band and wide undercoat; a few broad bands and wide undercoat or multiple thin bands (as seen in the background colour of Silver Tabbies).
Burmilla breeders who rarely saw tipped cats in early generations, but saw them frequently in later generations, even suggest that in addition to dominant wide-band there may be a second recessive "super wide band" gene for tipping. However these effects are equally attributable to inheriting either one or two copies Wb.
In goldens, wide band refers to the yellow banding of the hair shaft. Wide-band would have no effect on a non-agouti cat as the hair shafts are not banded. A eumelanin series cat (black/brown) can have the recessive form of inhibitor gene (golden), but doesn't have true red pigment (phaeomelanin), so the undercoat is warm cream or apricot rather than bright golden. For that reason, it's suggested that some poor quality silvers are really creamy goldens that give the illusion of having silver.