Two colors are used to achieve this herringbone look. Instructions are included for a 2.5-litre hot water bottle and a 1.75-quart (2-litre) hot water bottle. A side zip can be included to provide easy insertion and removal of the hot water bottle, or alternatively, insert the (rolled-up) hot water bottle through the top opening.
Note: as most rows are worked over the top of previous rows, this pattern results in a thicker cover.

As well as written instructions - UK and US terminology, the pattern includes charts to provide guidance.