Why are there stain marks to be found on the fabric adjacent to the zip?
Check for any solution / sprays / polishes being used on the zip teeth. Check for any excess oil being used on sewing threads if sewn application or check temperature of heat seal if sealed zip application.
Why are there stain marks to be found on the leather adjacent to the zip?
Check for any solution / sprays / polishes being used on the zip teeth. Check for any tanning chemical residues on the surface of the leather. Check that the zip has been ordered with Protecto Treatment to prevent any reaction of the pigments In the leather with the copper of the zip.
How can I resolve boilersuits being returned with teeth missing?
Coats Opti recommends spiral zips for workwear. Check that slider is closed during laundry and check button is fastened and bar tack protection offered to the bottom of the zip.