Round Braid / Flat Braid

Definition and Overview

Round braid and flat braid are names mainly used to distinguish the shape of braided cords and similar items. Round braid has a cross section that is close to circular, while flat braid has a band-like, flat shape. Both are basic terms used when specifying the thickness or width of a cord, its surface feel, and how it feels in use.

“Braid” is an expression derived from the cord-making process of braiding yarn to make a cord. However, in distribution, knitted cords and woven cords are also sometimes called round braid or flat braid, so the name alone may not identify the manufacturing method.

Materials and Structure

Materials include cotton, polyester, nylon, acrylic, and rayon. Strength, luster, stiffness, fuzzing, and stretch vary greatly depending on the material, yarn thickness, twist, and braiding density.

Round braid is often made by crossing multiple yarns in a three-dimensional structure, giving it thickness and a three-dimensional feel. Flat braid is made by spreading the yarns out in the width direction, making it easier to lie flat. Those with a buttonhole thread core may be easier to keep in shape.

How Dimensions Are Expressed

Round braid is generally expressed by diameter or thickness, while flat braid is expressed by width. However, because the cross section changes depending on the structure, load, and processing condition, the indicated dimensions should be checked as a standard reference. If necessary, thickness should also be checked.

Cords for apparel must match the opening, cord stopper, cord end, and knots. Round braid is easier to pass through, while flat braid is easier to select when you check the visible width and how it feels against the skin using an actual sample.

• Round braid: check the diameter, thickness, and whether there is a core.
• Flat braid: check the width, thickness, and how easily the edge frays.
• Common: check narrowing during extension, width changes, and how it passes through hardware.

Main Uses and How to Choose

Round braid is used for hood and waist drawcords, bag cords, loops, and similar items. It has a three-dimensional feel and is easy to thread, and it gives knots more volume, but thin types may feel like they dig in.

Flat braid is used for apparel waist cords, bag drawstrings, decorative tape-like cords, and similar items. It follows flat surfaces well and, depending on the width, can create a decorative effect. Choose the tensile strength, resistance to slipping, and hand feel needed for the application.

Handling and Sewing Notes

On braided cords, the yarn may unravel or fray from the cut end. Finish the end in a way that suits the specification, such as tying it off, stitching it in place, or attaching a cord end. Heat-sealing the end is limited to cases that include thermoplastic fibers, and the material specification and finished result should be checked in advance.

Stretching or shrinking during washing or drying, color transfer from dyed products, and fuzzing caused by friction vary depending on the material and structure. For products with cords threaded through the main body, take into account possible pull-out or tangling during washing, and review the specification including the end-fixing method, reinforcement of the opening, and washing tests.

Frequently Asked Questions