If the boy was young or of small build this whack most of his bottom each time as was preferred to a larger slipper, which would be heavier and more likely to bruise a young bottom, certainly where the tip landed. This may result in a parent’s complaint if they saw the bruise on the boy’s bottom when bathing him. Some PE teachers used the small slipper on larger boys as it was less likely to bruise, but here one of the slippers meant one whack on each cheek. Many boys found it stung a lot more when a small slipper was applied just to one cheek rather than a larger one right across the bottom.