My aunt told me that at her strict boarding school in Aberdeen during the 1950s the senior mistress would frequently administer a 12 stroke tawsing across the knickers of some naughty girls with the McRostie.
Since my aunt was not interested in receiving same she decided to invest in a pair of taswe-proof knickers that were advertised in the local newspaper. These knickers were made from a special titanium-aluminium alloy and consequently were relatively light (around 5.0 kg) and were available in the standard regulation school colours.