Wilcom Hatch Lettering Underlay: When to Trust Auto-Underlay (and When to Override It)

Creating Crisp Lettering in Wilcom Hatch: The Master Guide to Underlay

Lettering is the litmus test of an embroiderer's skill. It is the fastest way to make a project look professional, but also the easiest place to encounter "mushy edges," bunched thread knots, or gaps where the fabric shows through.

If you are following along in Wilcom Hatch, think of underlay not just as "extra stitches," but as the concrete foundation of a house. If you build a skyscraper on sand (no underlay), it sinks. If you build a shed on a massive bunker (too much underlay), it looks bulky and ridiculous.

In this white-paper-style guide, we will deconstruct Sue from OML Embroidery’s workflow in Hatch. We will move beyond the "default settings" and teach you the sensory and empirical indicators of perfect lettering.

The "Danger Zone": Small Lettering (<6mm)

When lettering drops below 6mm (approx. 1/4 inch), the rules of physics change. The needle penetrations are so close together that adding structure often causes "cluster jams"—where the thread builds up into a hard knot rather than a smooth letter.

The Physics of Small Stitches

Sue’s key insight is counter-intuitive: Less is more. If tiny lettering is bunching up, you don’t need a stronger foundation; you need to clear the way. There simply isn’t enough column width (often <1mm wide) to stack multiple layers of thread.

Hatch’s Auto-Logic: When you scale text down in Hatch, the software automatically switches to Center Run underlay (a single line traveling through the middle). This is critical because it anchors the fabric without fighting the satin top stitch for space.

Empirical Data & Safe Ranges

• Speed Limit: For lettering under 5mm, slow your machine down. If your machine runs at 1000 SPM (Stitches Per Minute), drop it to 600-700 SPM. This reduces needle deflection.
• Needle Choice: Use a 65/9 or 60/8 needle. A standard 75/11 needle leaves holes that are too large relative to the column width.

Step-by-Step: The "Clean Path" Inspection

1. Create your text object in Hatch.
2. Scale down to your target size (e.g., 5mm).
3. Zoom in (TrueView off) until you see the skeleton of the design.

Checkpoints (Sensory & Visual):

• Visual: You see a single line running through the center of the column.
• Visual: The underlay does not touch the edges of the column.
• Tactile (Post-stitch): The finished letter feels flexible, not like a hard BB pellet.

Pro Tip: The Stabilizer Variable

Software can't fix physics. If you digitize perfect small letters but hoop them on stretchy fabric with only tearaway stabilizer, they will distort.

• The Fix: Use cutaway stabilizer for knits.
• The Upgrade: If you struggle to hoop small items (like cuffs or collars) tight enough without potential "hoop burn," switching to magnetic embroidery hoops allows you to clamp dense, small areas securely without forcing the fabric into an unnatural distortion.

The "Sweet Spot": Standard Text (6mm–10mm)

6mm to 10mm is the standard size for left-chest logos and excessive names. Here, Hatch usually selects Center Run or Edge Run automatically.

Why Center Run Reigns Supreme Here

A center run creates a "ridge" for the satin stitches to drape over, giving the letter a slight 3D lift (loft) and preventing it from sinking into the fabric pile.

Commercial Context: The "Wavy" Letter Problem If your preview in Hatch looks perfect (straight columns) but your sew-out looks "wavy" or "drunk," the issue is usually fabric slippage, not underlay.

• Diagnosis: If the fabric feels loose in the hoop (trampoline test: tap it, it should drum), underlay cannot save you.
• Solution Level 1 (Technique): Use spray adhesive (temporary) to bond fabric to stabilizer.
• Solution Level 2 (Tool): Many professionals encountering this issue search for how to use magnetic embroidery hoop videos because the magnetic clamping force creates even tension across the entire surface, preventing the "pull" of the satin stitch from warping the fabric.

Heavy Duty: Jacket Backs & Large Text (>10mm)

When you scale up to "Jacket Back" size (letters 2 inches/50mm tall), satellite stitches become long and loose. Without a heavy foundation, they will snag, wobble, or expose the fabric underneath.

Sue’s Formula for Large Text: Structure + Definition.

1. Double Zigzag: Creates a truss-like structure to hold the column open.
2. Edge Run: Added on top to act as a "rail" for sharp, crisp edges.

Step-by-Step: The "Bunker" Stack

1. Select the large lettering object.
2. Open Object Properties.
3. Select Double Zigzag as your primary underlay.
4. Check the box for Edge Run as your secondary underlay.

Checkpoints:

• Visual: The preview shows a "net" (zigzag) encased by rails (edge run).
• Auditory: When stitching, large satin columns with heavy underlay produce a rhythmic, solid "thump-thump" sound. High-pitched whining suggests too much density.

Warning - Thread Breakage Risk: Heavy underlay + huge satin columns = high stitch count. If you hear a "popping" sound or experience thread shredding, your density may be too high. Increase your stitch spacing (e.g., from 0.40mm to 0.45mm) to let the thread breathe.

Precision Control: Customizing Margins

Sometimes, the underlay "peeks out" from under the satin stitch (poke-through). This usually happens on curves. Hatch allows you to pull the underlay back from the edge.

Step-by-Step: Adjusting the "Setback"

1. Select the lettering.
2. Navigate to the Stitching Tab in Object Properties.
3. Locate Margin from Edge.
4. Adjust:
   • Normal: Default. Good for 90% of jobs.
   • Medium/Wide: Pulls underlay further inside. Use this if your registration is slightly off or fabric is shifting.

Decision Criteria:

• Leave on Normal for crisp woven fabrics.
• Change to Medium for textured fabrics (pique polo shirts) where the nap might push the satin stitch around, risking underlay exposure.

Troubleshooting: "Why are my settings locked?"

If you cannot edit these settings, you are likely in the "Select" mode rather than "Reshape/Edit," or you have broken the lettering block into individual stitches.

Troubleshooting Logic: The Doctor’s Table

Use this logic flow to diagnose issues before changing software settings.

Decision Tree: Choosing Your Underlay

Don't guess. Measure your letter height and follow this path:

1. Is text < 6mm?
   • YES: Use Center Run only. If extremely small (<4mm), turn Underlay OFF.
2. Is text 6mm - 10mm?
   • YES: Use Center Run (Default).
3. Is text > 10mm?
   • YES: Use Edge Run for crisp borders.
4. Is text > 40mm (Jacket Back)?
   • YES: Use Double Zigzag + Edge Run.

Prep: The Pre-Flight Checklist

Before you digitize, you must ensure your physical setup can handle the design.

Hidden Consumables

• Needles: 75/11 for standard, 65/9 for small text. Ballpoint for knits, Sharp for wovens.
• Topping: Water-soluble topping is mandatory for towels or fleece to stop text from sinking.
• Lighter: To burn away fuzzy thread tails (carefully!) after trimming.

Prep Checklist

• Fabric Analysis: Is it stretchy? (If yes -> Cutaway stabilizer). Is it textured? (If yes -> Add Topping).
• Hooping Strategy: Do you have a machine embroidery hooping station or a defined surface to ensure the styling is straight?
• Machine Hygiene: Is the bobbin area clear of lint? Lint can cause random tension loops on lettering.

Warning: Magnetic hoops contain strong magnets. Keep them away from pacemakers, and watch your fingers—they can pinch severely if snapped together carelessly!

Setup: Hatch Workflow

Executing the setup in Wilcom Hatch.

1. Open Lettering Docker: Type your text.
2. Resize First: Do not adjust underlay until you have sized the text to final dimensions.
3. Change Color: Switch to a high-contrast color (like Red or Black) to see the underlay structure clearly against the background.

Setup Checklist

• Text is sized correctly.
• Object Properties > Stitching Tab is accessible.
• Underlay type matches the "Decision Tree" above.
• Stitch Density is standard (0.40mm) unless utilizing specialized thread using thicker weights (e.g., 30wt).

Operation: The Stitch Out

Efficiency Note for Production

If you are running names on 50 shirts, digitizing is only 10% of the job. The bottleneck is hooping.

• Level 1 Efficiency: Use a hooping station for machine embroidery to ensure every name is at the exact same height.
• Level 2 Efficiency: If you are spending more time changing thread colors than stitching, this is the trigger point to look at SEWTECH Multi-Needle Machines. The ability to set up 15 colors at once changes lettering from a chore into a profit center.

Operation Checklist

• The "Click" Test: You heard the hoop snap or magnet engage firmly.
• The Trace: You ran a trace/contour check to ensure the needle won't hit the hoop.
• The Watch: You watched the first letter stitch out. If the underlay loops, stop immediately—check upper tension.

Results

Underlay is not a "set it and forget it" feature; it is a variable that connects your digital design to the physical fabric.

• Small Text: Needs breathing room (Less Underlay).
• Large Text: Needs a skeleton (More Underlay).
• Wavy Text: Needs better workholding (Magnetic Hoops).

By mastering the correlation between Letter Size and Structure, you eliminate the "amateur look." To guarantee that your perfect digital file results in a perfect physical patch or shirt, consider standardizing your physical workflow with a hoop master embroidery hooping station style setup or high-quality magnetic frames. Consistency in the hoop equals crispness in the stitch.