Bi-loaf 1 (or half bakery or loaf on loaf) is a still life that makes up half of a bakery (and is made up of two loaves). When the term bi-loaf is used, this pattern is its most common meaning.
There is a remarkable reaction where a glider collides with the bi-loaf, displacing it by (3,6) and generating another glider in the same direction as the incident glider. The only other known reactions of this type involve stable reflectors, which have a displacement of (0,0). It can also act as a one-time glider reflector.
Bi-loaf 1 is the eleventh most common still life in Achim Flammenkamp's census, being less common than barge but more common than mango. It is also the fifteenth most common object on Adam P. Goucher's Catagolue.