Seam Allowance

Seam allowance refers to the extra fabric provided beyond the pattern's cutting line that allows for the joining of fabric pieces. It plays a crucial role in garment construction, determining the ease of sewing and the final fit of the garment. In the United States, the most common seam allowance used on American patterns is 5/8 of an inch (approximately 1.6 centimeters).

The 5/8 inch seam allowance has become the standard in American sewing patterns for several reasons:

1. Tradition and Consistency: Over time, the 5/8 inch seam allowance has become a widely accepted convention in American patternmaking. It offers consistency and allows for easier pattern sharing and adaptation among different brands and designers. By adhering to this standard, sewers can confidently use patterns from various sources without the need for extensive modifications.
2. Versatility: A 5/8 inch seam allowance provides enough room for adjustments during garment construction. It allows for minor modifications, such as letting out or taking in seams for a better fit, without compromising the overall design and structure of the garment.
3. Seam Finishes: A 5/8 inch seam allowance offers flexibility when finishing seams. It allows for a variety of seam finishing techniques, such as serging, zigzag stitching, or binding, without encroaching on the actual seam line. This versatility enables sewers to choose the most suitable seam finishing method based on the fabric type, garment style, and personal preference.
4. Compatibility with Sewing Machines: Many sewing machines are designed to accommodate a 5/8 inch seam allowance as the standard setting. This makes it easier for sewers to stitch accurate seams without having to adjust the machine settings for every project. Additionally, commercial presser feet and attachments often have markings and guides specific to a 5/8 inch seam allowance, further enhancing sewing precision.

While the 5/8 inch seam allowance is the most common in American patterns, it's important to note that there can be variations depending on the type of garment, pattern brand, or specific sewing techniques. Some patterns, particularly those for specialized garments like lingerie or children's clothing, may have narrower or wider seam allowances. It is always advisable to consult the pattern instructions and follow the indicated seam allowance for the best results.

The 5/8 inch seam allowance is the most frequently used seam allowance on American patterns. Its widespread adoption offers consistency, versatility, and compatibility with sewing machines, making it convenient for sewers to work with a wide range of patterns. Understanding and adhering to the specified seam allowance ensures accurate construction and helps achieve well-fitting, professional-looking garments.