How to Fix Fill Stitch Extending Beyond the Outline in Embroidery?

The client noticed that the fill stitch was going outside the outline.
Because of this, the edges did not look clean.
The design looked a bit rough, especially around small areas.
This became a problem because the client was planning a bulk order and needed a clean result.

After checking the stitch-out and talking to the client, we found that:
The design file was correct
The outline and fill were properly made
There was no mistake in digitizing

Then we checked the setup:

The client was using only one layer of bottom stabilizer
Fabric was moving slightly during stitching
This small movement made the fill go outside the outline
👉 So the problem was not the design, it was fabric movement

We guided the client to adjust the setup:

Use two layers of bottom stabilizer
Keep the top stabilizer
Hoop the fabric tightly
The client followed these steps and ran another stitch-out.

When the fabric moves, stitches don’t land in the correct position.
By improving stabilization:
The fabric stayed firm
The stitches stayed in place
The fill remained inside the outline