The 15th-century artist placed these tiny details in formation, like an arrow aimed at the cross.
The significance of three tiny details in this 15th-century painting far outweighs their size. At the foot of the ladder on the left are the nails used to crucify Christ. These symbols of the Passion don’t usually feature much in art, unless they are being driven into or taken out of the victim’s body. This didn’t prevent them from becoming a highly contested issue among Christians. Some believed fervently that there were three, and others four.
We know that ropes were not used on this occasion, as there would have been no pierce wounds afterwards. The Romans used nails often and must have recycled them. There are very few surviving examples, considering the number of crucifixions that took place in the Roman empire. Six thousand of Spartacus’ followers were executed in this manner on the main road into Rome.