I grew up in the 1950s and was sent to an all boys private school by my parents. In those days, corporal punishment was commonplace and I’ve lost count of how many times I’ve received it, or how many other boys’ bare bottoms I’ve seen getting the same.
Without exception, every incidence of CP I witnessed was administered on the bare buttocks. Although you could be sent to the headmaster for a real hiding, the cane was in regular use in class.