The strap or tawse was used in schools to punish errant pupils. 

It is thought to be less severe than a cane or birching rod.  Regardless of this

due to the width of the straps in comparison to the other two mentioned it covers a larger

 area of the buttocks or palms,

therefore the area is in fact taking more punishment even

though it may not leave the same amount of bruising and stripes.

Generally a strap mark depending upon its severity will fade within

hours.   Unless the skin becomes chaffed with repeated strokes

on the same area.  Leaving a marking that will resemble that

of a carpet burn type injury.  Wet and weepy and extremely pain-

full especially when water or antiseptic is applied. 

I have just recently purchased a lovely mummy strap with

precision holes through the length of the tail, an extra heavy

3 tail lochgelly tawse ,  and strap to match.  Finishing off

with a genuine replica Canadian prison strap.