How Much Interfacing Should Be Cut: A Guide for Sewing Projects

Sewing projects often require the use of interfacing to add structure, stability, and support to various parts of garments or accessories. However, when it comes to how much interfacing should be cut, many sewists find themselves puzzled. The amount of interfacing needed can vary depending on the project, the fabric, and personal preferences. To guide you through this dilemma, it’s important to consider factors such as the weight and drape of the fabric, the intended purpose of the interfacing, and the desired outcome of the finished project. By understanding these key elements, you can make informed decisions on how much interfacing to cut and ensure that your sewing projects are both functional and aesthetically pleasing. Additionally, using high-quality threads, such as the Madeira Aerolock Premium Serger thread, can further enhance the durability and longevity of your creations, offering confidence that your hard work will withstand the test of time.

Do You Cut Interfacing With Seam Allowance?

When it comes to sewing projects that require interfacing, one common question that arises is whether or not to cut the interfacing with seam allowance. The answer to this question depends on the specific project and the desired outcome.

This is especially true when working with delicate fabrics or fabrics that fray easily. By cutting the interfacing with seam allowance, you create an extra layer of protection for the fabric, preventing it from fraying or unraveling. This can be particularly important for garments or accessories that will be subject to frequent washes or strain.

For example, if you’re using a high-quality interfacing that’s already sturdy and doesn’t require additional reinforcement, there may be no need to add extra bulk to your project by including seam allowance. In such cases, trimming the interfacing to match the pattern piece exactly can result in a cleaner, more professional-looking finished product.

If in doubt, you can always test a small scrap of fabric and interfacing to see how they behave when cut with or without seam allowance.

How to Choose the Appropriate Interfacing for Different Types of Fabrics.

When choosing the right interfacing for your sewing projects, it’s important to consider the type of fabric you’re working with. The weight and drape of the fabric, as well as the desired effect, will influence the interfacing selection.

For lightweight and delicate fabrics like silk or chiffon, a lightweight interfacing is recommended to maintain the fluidity of the fabric. Medium-weight fabrics like cotton or linen will benefit from a medium-weight interfacing that provides stability without adding too much bulk.

When working with heavy or structured fabrics such as denim or wool, a heavyweight interfacing is ideal to provide the necessary support and structure. It’s important to ensure that the interfacing matches or complements the weight and stiffness of the fabric for the best results.

Additionally, consider the desired effect of your project. Fusible interfacings are convenient and easy to use, as they can be ironed onto the fabric. Sew-in interfacings offer more control and precision, but require extra sewing steps.

Remember to test a small swatch of your fabric with different types of interfacing to determine the best match before applying it to your entire project.

By taking into account the fabric type and desired effect, you can confidently choose the appropriate interfacing to enhance the overall quality and appearance of your sewing projects.


Understanding the different types of interfacing available, such as fusible, sew-in, or knit, can aid in making informed decisions. Additionally, considering the level of support required for the garment or project is crucial. While there are general guidelines available, each project may require adjustments or customization. By investing in top-notch supplies and adapting to individual project needs, one can achieve professional and successful sewing results.

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