Understanding underlay

Author: Lindee Goodall  

Understanding underlay main image

First of all, what exactly is underlay? Underlay is the skeleton of an embroidery design; stitches that are laid down before the upper decorative stitches. Just as the bones of your skeleton provide support for your body, so does underlay support a design. Underlay is the foundation of a design and provides stability to maintain design integrity.Simply put, proper underlay is vital to good embroidery results.

Purposes of underlay

The two primary purposes of underlay are to stabilize the fabric by attaching it to the stabilizer and to support the top stitching. Think of underlay as a way to initially baste the fabric to the stabilizer. The best way to do that is with what is known as an edge walk, which is a simple “outline” of the design set within the edges of the cover stitching. On very small objects it may simply be a line of running stitches up the centre, known as a centre walk. On larger areas, this edge walk is followed by a light fill or zigzag as required by the fabric. In extreme cases, this light fill will be replaced with a mesh or grid of stitches. In this respect, underlay reduces fabric shifting during the sewing process, thereby also reducing puckering.

Proper selection and use of underlay reduces the push and pull distortion resulting from machine thread tensions. By attaching the fabric to an appropriate stabilizer, the fabric – even very unstable ones – acquires the stability qualities of the backing used. Caution! There are other causes of fabric puckering that won’t be cured with underlay. These include poor hooping techniques, poor or inadequate stabilizing choices, and tight machine tensions, especially when combined with polyester thread.

Underlay supports the top stitching by maintaining a crisp, well-defined edge between abutting areas of stitches. Underlay also prevents stitches from sinking into the fabric. Highly textured fabrics like terry cloth towels can benefit from a light “net” of underlay to hold down the nap and provide a smooth, even surface for later stitches. Digitizers also employ underlay creatively to add additional loft to some sections of embroidery to add interest, depth, and realism.

What if underlay is removed?

Unless you know what you are doing, I do not recommend removing underlay. Worst case – think free-standing lace – your entire design will just disintegrate into a wad of thread once the stabilizer is removed. Most often, you will have varying ranges of lower quality embroidery depending on a range of factors. Design, fabric and stabilizer choices, along with hooping techniques will have the most influence. I have heard educators recommending the removal of underlay to reduce design thickness, stitch count, and sewing time. However, unless you are sewing on a “non-fabric”– leather, unbacked vinyl, wood, metal, paper – where needle penetrations actually puncture the material and leave a hole, this is rarely wise on a professionally digitized design. Experienced, professional digitizers know that more underlay is not necessarily better and that it should be precisely, concisely, and strategically placed. If the underlay in your design appears random or scribbled, I’d question the quality of the design.

When is underlay not required?

You won’t find underlay on designs that are composed of just running stitches like redwork designs or quilting designs. Running stitches don’t create as much distortion as fills and satins. Even if you wanted underlay, there would be no way to hide it. You can however, use your machine’s baste function to run some intial stitching to attach your fabric to the stabilizer.

When should I add more underlay?

If you are sewing on a lofty, textured fabric, you may need to add more underlay. This is really only easy if you created the design yourself in your digitizing software or lettering program or if you have the original design and it was created in the same software you have – unlikely with stock designs. Adding underlay is beyond the scope of this article, I just wanted to point out that it may be necessary and it can be done.

Remember

Underlay has a purpose. In this article we’ve only discussed an overview of underlay and what you need to know as an embroiderer. Before modifying the underlay, examine it on screen and perform a test sew. If you do modify, only work on a copy of the original design. Keep in mind that underlay in stock designs is targeted for “average fabric” and may not be optimal for your project. Optimizing underlay is most useful in production environments.

Want to know more?

If this whetted your appetite and you’d like to know more about how a design is constructed so that you can maximize your results, I’ve written an 106-page book called Anatomy of a Design: How to Think Like a Digitizer and Become a Better Embroiderer that will teach you how a digitizer looks at designs.