Albert Barnes on Matthew 27:28

And they stripped him. That is, they either took off all his upper garments, or removed all his clothing, probably the former.

A scarlet robe. Mark says they clothed him in purple. The scarlet colour was obtained from a species of fruit; purple from shell-fish. The ancients gave the name purple to any colour that had a mixture of red in it, and consequently these different colours might be some- times called by the same name. The robe here used was the kind worn by Roman generals, and other distinguished officers of the Roman army, and also by the Roman governors. It was made so as to be placed on the shoulders, and was bound around the body so as to leave the right arm at liberty. As we cannot suppose that Pilate would array him in a new and splendid robe, we must suppose that this was one which had been worn and cast off as useless, and was now used to array the Son of God as an object of ridicule and scorn!