A palomino mare with the tobiano pattern. Photo courtesy of CheyAut Ranch
Tobiano is probably the best recognized of all the white patterns. It almost always leaves the legs white. It will cross the top line at the shoulders and hip before other areas and fights to leave the chest, flanks and head colored. It commonly results in a solid head and white tale head. Some theorize that Tobiano doesn't add face white but whether this is true or not is still open for conjecture. When Tobiano is mixed with other patterns we can get a solid white or nearly white horse but rarely, if ever, does Tobiano express to that extent alone. When Tobiano is very minimal (sometimes called Crypt-Tobiano). It will usually express as four white stockings or socks, sometimes with a wither or neck spot. In miniature horses, it's expression can found at it's most minimal, at times leaving only the back two feet white.
Horses can have a great variety of white patterns. All of the following white patterns can occur on any color horse, with any combination of dilutions, modifiers, and other white patterns. For example, it is completely possible to have a tobiano/sabino/splash/roan/palomino. However, while it is possible, not all horse breeds carry all white patterns and dilutions, and possible does not equate to a likely outcome. All white patterns can also be present in minimal and maximal forms. Minimal can be very minimal indeed (think white spot on the bottom of a hoof for frame), and maximum expression can be almost completely white, especially when more than one pattern is present.
Photo Submitted by Emily West Homozygous Tobiano Stallion with Frame Homozygous for Black as Well