Fusible Lining is used in the construction of textiles to add structure and support. It can be made from woven or knitted fabrics such as cotton, wool, and many synthetic materials. It can also be a blend of different fibers and materials to achieve certain performance characteristics such as stretch and strength. It can be used as sew-in interfacing or as an underlining for garments such as dresses and pants. It can be purchased either online or from fabric stores in sheets, rolls, or tiny tapes depending on the type of project you are working on.
Woven fusible interlinings are a staple in any fashion designer’s kit and two types of woven fabric can be used for this purpose – lock knit and weft insert. Both these forms of woven interlinings have their advantages and disadvantages but they both offer good tensile properties. However, there is a trade-off between the tensile strength of the interlining and its ability to allow movement in the direction of the warp threads. The weft-inserted variety of interlining is a newer innovation and offers some stretch in the weft direction but it may be slightly more costly than the locking knit version.
It can be bonded to the outer fabric using heat from an iron. It can be fused to the inside or outside of the garment – although fusing to the inside will help reduce bulk on the seam allowances. It is normally trimmed to reduce bulk and this can be done before or after fusing. Often the pattern pieces will have seam allowances included but it is often easier to interface a block of the fabric and then trim it down before cutting out your pattern.
When fusing, the interlining should be placed on top of the shell fabric. The heat from the iron melts the glue on the underside of the interlining which then adheres to the face of the shell fabric. The fusing temperature is usually between 130 and 160 degrees C. If the fusing temperature is too high, there will be an excessive flow of adhesive from the resin which may result in a strike-back or strike-through effect on the fabric. If the fusing temperature is too low, the adhesive will not bond to the shell fabric.
After fusing, the interlining is usually pressed for a few minutes to set the adhesive layer. It is then ready for cutting or sewing. Some creases or wrinkles in the interfacing are inevitable but these can be easily corrected by heating it again and re-pressing. Usually, it is best to iron the interfacing on a smooth surface but if you are using it for a project that requires precision then you can use a small pressing sheet to avoid any creases or wrinkles.
When choosing fusible interfacing, there is a direct correlation between the weight of the fabric and the weight of the interfacing needed (for example heavier fabric needs heavier interfacing). It is important to choose the right interfacing for your project as it will determine the final look and feel of the finished garment. If the interfacing is too light then the garment will appear stiff and unstructured.