Colin Berry never ceases to amaze with Might the Shroud image have been produced as a thermochemical scorch on linen? Quicklime?
[ . . . ] Given that a dead body does not produce sufficient heat to scorch linen (for which a temperature of 200 degrees Celsius or more is required) then the thinking so far has been that an effigy of a real person, e.g. a bronze statue, was deployed. However, I’m as conscious as the next man of the practical difficulties of imprinting successfully off a life-size effigy. Mistakes would be costly, given the price of quality linen,
So this morning, I got to wondering about alternatives to metal templates that have been heated, say, over coals. Might an exothermic reaction using a chemical have been used instead – but a common one available in medieval times?
He definitely wants you to look at this blog. You should.