CB
Initialism of center back, a line marking the center on the back side of a piece of clothing.
CB: the center line marked on fabric backs
In textile production, CB stands for center back, a marked line running vertically down the midpoint of a garment's back panel. This line serves as the primary reference point for symmetry, grading, and construction during cutting, sewing, and pressing. It ensures that back panels are balanced and that pattern pieces align correctly when sewn together.
The CB line is typically marked during the lay-planning stage, before cutting begins. Pattern graders and cutters use it to orient pattern pieces on fabric and to maintain grain line alignment. On woven fabrics, CB usually runs parallel to the selvage; on knits, it aligns with the course direction. The line may be indicated by a notch, a mark made with tailor's chalk, or a small cut in the seam allowance, depending on the garment type and production method.
Where CB appears in garment production
CB is essential in patterning because it defines how a back panel sits on the body. Many garments, from shirts to trousers to coats, are cut with a CB fold, meaning the pattern piece is placed so that one edge of the pattern aligns with a fold in the fabric, automatically creating a symmetrical back. Without a clear CB reference, back panels can twist or slope during sewing, creating fit problems and uneven hem lines.
Grading (scaling patterns up and down in size) relies heavily on CB as an anchor point. Grade lines radiate outward from CB, so the line remains stable while width and length increase. This prevents diagonal distortion in larger sizes. Pressing teams also use CB markings to position back panels on forms and steamers, ensuring consistent shape and hang across production runs.
CB differs from CF (center front) in function and visibility. The front of most garments is sewn from two separate panels that meet at a center seam or placket, whereas the back is often cut as a single piece. Some production systems mark CB only as a guide during cutting and remove it before shipment; others leave a subtle notch or thread mark that tailors use as a reference during alterations.