In the world of digitizing for embroidery, there’s one element that often goes unnoticed by beginners but makes a world of difference in the quality of the finished design: the underlay stitch.
Underlay stitches act as the foundation of embroidery. Much like the hidden structure in a building, they stabilize the fabric, control distortion, and prepare the canvas for top stitches. While customers may never see them, professionals know that without underlay, even the most artistic design can fall apart.
This comprehensive guide explores why underlay stitches matter, the types you need to know, best practices for digitizers, and how they directly affect embroidery outcomes in 2025 and beyond.
What Exactly Are Underlay Stitches?
Underlay stitches are preliminary stitch runs applied before the main embroidery design is stitched. They:
- Anchor the fabric to prevent shifting.
- Create loft so top stitches appear smoother.
- Reinforce the design for durability.
- Manage push and pull effects during embroidery.
In short, underlay is the “hidden hero” that separates professional-quality embroidery from amateur results.
Why Underlay Is Critical in Digitizing for Embroidery
1. Stabilization Across Different Fabrics
Every fabric behaves differently when stitched.
- Stretch fabrics (jersey, polyester) tend to distort.
- Heavy fabrics (denim, canvas) need stronger support.
- Delicate fabrics (silk, organza) require minimal but strategic underlay.
- Without underlay, top stitches either sink in, distort, or lose definition.
2. Professional-Grade Stitch Quality
Top stitches lay cleaner, sharper, and more consistent when underlay is used properly. It ensures the embroidery design looks as good on fabric as it does on screen.
3. Durability Over Time
Embroidery on uniforms, caps, and sports gear faces frequent wear and wash cycles. Underlay strengthens designs, preventing unraveling and maintaining shape for years.
4. Push-Pull Compensation
Embroidery machines naturally cause fabric to “push” in one direction and “pull” in another. Underlay counteracts these forces, maintaining proportion in shapes and letters.
5. Efficient Thread Usage
Although it seems like “extra stitching,” underlay often reduces the number of top stitches needed, saving both thread and production time.
The Four Most Common Types of Underlay Stitches
1. Center Run Underlay
- A simple stitch running down the middle of a shape.
- Ideal for small letters and thin satin stitches.
- Prevents distortion without adding bulk.
Pro: Saves time and thread.
Con: Limited stability for large areas.
2. Edge Walk Underlay
- Outlines the edges of a shape.
- Keeps borders sharp and crisp.
- Perfect for satin stitches in lettering and logos.
Pro: Prevents fraying or uneven edges.
Con: May not provide enough support alone on unstable fabrics.
3. Zigzag Underlay
- A zigzag pattern beneath satin areas.
- Adds loft, especially useful for metallic or thick threads.
- Widely used in puff embroidery and bold lettering.
Pro: Smooths out textured fabrics.
Con: Can make designs too heavy if density isn’t managed.
4. Tatami (Fill) Underlay
- A light version of fill stitching used beneath large areas.
- Covers fabric well, preventing show-through.
- Best for logos with large blocks of color.
Pro: Superior stabilization for big areas.
Con: Increases stitch count significantly.
How to Choose the Right Underlay for Different Fabrics
- Cotton polos: Edge walk + zigzag.
- Caps: Edge walk underlay to maintain curves.
- Sportswear (polyester blends): Center run + zigzag to prevent distortion.
- Denim: Tatami underlay for large filled areas.
- Silk: Minimal underlay—use light center runs.
Step-by-Step Workflow: Adding Underlay in Digitizing
- Analyze the artwork — Look for elements that need extra support.
- Assess fabric type — Choose underlay based on stretch, thickness, or texture.
- Select underlay type — Center, edge, zigzag, or tatami (often combined).
- Adjust density — Avoid too dense underlay; balance is key.
- Set stitch direction — Underlay should cross the top stitch angle for stability.
- Test sew-out — Always run a sample before mass production.
Software Features for Underlay in 2025
Modern digitizing software such as Wilcom, Hatch, Brother PE-Design, Pulse, and Floriani has advanced underlay settings. These allow digitizers to:
- Set custom density and angles.
- Choose from automatic underlay presets.
- Combine multiple underlays in one shape.
- Simulate stitch flow before production.
Still, software defaults should not replace human expertise. Skilled digitizers often override auto-settings for complex fabrics or designs.
Case Studies: Underlay in Real-World Embroidery
Case 1: Corporate Polos
A company logo with small lettering on polo shirts puckered without underlay. Adding edge walk + center run stabilized the letters, giving them crisp definition.
Case 2: Sports Jerseys
Athletic jerseys made of stretchy polyester distorted logos. Zigzag underlay prevented fabric pull, ensuring the brand logo looked sharp on every uniform.
Case 3: Cap Embroidery
Curved surfaces on caps often distort designs. Edge walk underlay maintained design consistency, while zigzag helped stitches sit smoothly.
Case 4: Babywear
Soft cotton baby clothes needed light density underlay to prevent bulk, ensuring comfort and durability.
Common Mistakes in Underlay Digitizing
- Skipping underlay completely to “save time.”
- Using only one type of underlay for all fabrics.
- Overcompensating with dense underlay, leading to stiff embroidery.
- Ignoring specialty thread needs (e.g., metallics require zigzag).
Myths About Underlay in Embroidery
- Myth 1: Underlay is a waste of thread.
- Truth: It saves top thread by improving coverage.
- Myth 2: Auto settings are always enough.
- Truth: Manual adjustments are often necessary.
- Myth 3: Small designs don’t need underlay.
- Truth: Even tiny letters benefit from center or edge walk.
Why Underlay Matters More in 2025
With the rise of AI-driven digitizing tools and faster commercial machines, designs are being stitched at higher speeds than ever before. This increases the importance of underlay as it prevents thread breaks and ensures quality even in high-volume runs.
Brands expect embroidery to look flawless across multiple fabric types something only strong underlay planning can guarantee.
Conclusion
Underlay stitches are the invisible foundation of every high-quality embroidery design. They stabilize fabric, prevent distortion, enhance coverage, and extend design durability. Skipping or misusing underlay is one of the most common mistakes in digitizing, often leading to poor stitch quality and wasted production time.
By understanding fabric types, choosing the right underlay, and mastering digitizing software, you can ensure every design looks polished and professional. When it comes to digitizing for embroidery, underlay isn’t optional—it’s essential.
For businesses seeking professional results, partnering with expert services like Emdigitizing ensures your designs are digitized with precision, underlay included.
FAQs
Q1. What happens if I skip underlay stitches?
Your design may pucker, distort, or sink into the fabric, resulting in poor stitch quality.
Q2. Which underlay is best for logos on caps?
Edge walk underlay is most effective as it keeps edges clean on curved surfaces.
Q3. How dense should underlay stitches be?
They should be lighter than top stitches—just enough for stabilization without adding bulk.
Q4. Can software automatically apply underlay?
Yes, but professional digitizers often customize it for better accuracy.
Q5. Do specialty threads like metallics need different underlay?
Yes, metallic threads benefit from zigzag underlay to reduce friction and breakage.
Q6. Is underlay always visible in the final design?
No, underlay is hidden beneath the top stitches but makes them smoother.
Q7. How do I test if my underlay settings are correct?
Run a test sew-out on the actual fabric before large-scale production.
