LIghtweight with some stretch.  This women's cut button up shirt is best worn open over a tank if you're busty.  Rachel is pictured in the Medium and Ashley is in the size XL (normally a size large)

Fabric

97% Cotton 3% Spandex

Size Chart

Small 2-4

Medium 6-8

Large 10-12

XLarge 12-14

1X 14-16

2X  16-18

3X 18-20

Measurements:

From shoulder to bottom seam, size M has a length of  27 inches

Bust width on size M is 36  inches

From shoulder to bottom seam, size 2X  has a length of  28 inches

Bust width on size 2X  is 48 inches