Seam allowance is the space between the edge of your fabric and the line where you sew your seam. It is the extra fabric that allows your garment pieces to be stitched together.
Traditional commercial sewing patterns often include a ⅝ inch (1.6 cm) seam allowance. Some modern indie patterns use ⅜ inch (1 cm), especially for stretch garments.
Katkow patterns are designed slightly differently. Most of our patterns include a ½ inch (1.27 cm) seam allowance. This size is beginner friendly and easier to sew accurately, especially when working with stretch fabrics.
If you prefer a smaller seam allowance, you can reduce it while sewing, but you must stay consistent throughout the entire garment to maintain proper fit.
You can also experiment with different seam finishes. You may serge the raw edges together after sewing and trim excess seam allowance if desired. For non-stretch garments, you can try French seams for a clean enclosed finish, rolled seams for lightweight fabrics, or finish edges with double folded bias tape.
Keeping your seam allowance consistent is important for accurate sizing. Sewing too wide or too narrow can change how the garment fits your body.
If you are unsure, use the seam allowance guides marked on your sewing machine plate, or measure and mark your seam line with chalk before sewing.
Understanding seam allowance ensures your pieces align properly and your finished garment matches the intended size.