Laminated croissant dough is cut into triangles before it is rolled. Each triangle is stretched or positioned with its point facing outward, then rolled from the wide base toward the tip to create the familiar layered pastry.
The dough becomes laminated when butter or another solid fat is enclosed between sheets of dough and repeatedly rolled and folded. This creates alternating dough-and-fat layers. During baking, water in the dough and butter turns to steam, helping separate the layers while the fat contributes richness and flakiness.
After cutting, a croissant triangle is usually rolled through roughly three and a half to four full turns. Bakers may then curve the ends inward to produce a crescent, although many butter croissants are sold in a straight shape. The exact dimensions of the triangles influence the pastry’s length, openness, and final volume.
Rectangles, circles, and squares are common shapes for other pastries, but they do not create the tapered roll needed for a traditional croissant. The triangle’s broad base supplies the body, while its narrowing point forms the outer tip.