This is a picture of an extant garment.

Note the deep triangular inset.

Detail from Brueghal's Massacre of the innocents.

The man in the party-colored tunic on the left and the man in green on the right both appear to have inset collars.

Detail from Carpaccio's Martyrdom of the Pilgrims

2 piece U shaped inset.

Detail from di Bartolo's Enlargement of the Hospital.

One piece U shaped inset with 2 piece back.

Detail of Mantenga's Martyrdom of St. Christopher.

The archer with the split back doublet and possibly one of the people in the window.

Detail of Veronese's Wedding Feast at Cana

Man in Green upper left corner.

Carpenters. Image number 848 in Milla Davenport's The Book of Costume.

Doublet pattern from Alcega's pattern book.

The piece in the upper right corner is the front collar piece. The piece to the left of it is the doublet back, note the collar extension.