Convertible collar is a pointed collar.It is worn with the neck button either fastened or unfastened.
A-B= ½ neck line of front and back +¼”.
Draw perpendiculars from A and B.
A-C =collar width=3½” or to taste.
A-C = B-D.
Mark H on B-D such that B-H =¾”
Produce C-D to E such that D-E =1 ¼”
Join H-E and produce to F such that E-F = ½”
G is midpoint of A-B.
Shape curve G-B and curve C-F as shown in the figure.