This ppt will help you know the various causes of defects due to a simple operation of embroidery. Check out the full article on link.

2. Embroidery defects can be a result of
irregularities in the stitches or the design or
both

3. 1. Poor Registration:
This defect appears when
the embroidery’s design
and stitches don’t align
correctly

4. 2. Fabric Grin/Gapping:
In this defect the base
fabric is visible from the
embroidery, either from
between design or
patterns
or on the edge of the
embroidery

5. 3. Missed Trim:
Appearance of extra
embroidery threads left
between patterns or other
design elements in the
embroidery

6. 4. Bunching at Corners:
The corners of the design
or letters in the
embroidery
are not crisp due to
gathering up of thread at
one point

7. 5. Poor Stitch Balance:
In this defect, the bobbin
thread shows up on the
top
side of the embroidery

8. 6. Fabric Damage:
Damage caused to the
fabric due to repetitive
needle penetration,
especially around the
corners of the embroidery

9. 7. Thick Embroidery:
Embroidery being too
dense or thick at some
places

10. 8. Poor Stitch Density:
Base fabric visibility
through the embroidery
due to low stitch density

11. 9. Poor Hooping: The
fabric surrounding the
embroidery gets distorted
or crumpled and cease to
lay flat on a surface

12. Visit www.stitchdiary.com
to read the full article on Embroidery Defects

13. Image Sources:
 https://lindeegembroidery.com/troubleshooting-embroidery-quality-issues/
 http://www.amefird.com.my/embroidery_quality.htm