The carthusian Sign of the Cross: in making the Sign of the Cross, whether upon oneself or things, the thumb and the first two fingers are fully extended, and the remaining two fingers are bent upon the palm of the hand. The Sign of the Cross of the Carthusians, is made reverently, slowly, with majesty; their gesture describing a uniquely large cross, from forehead, to waist, with their hands brushing the outside of each shoulder, left to right shoulder. It is important to make it well.

Quies

… a large cross with the thumb and with the two fingers, from above the forehead down to the breast.

Ancrene Wisse