used by drycleaners and spotters.
The first thing that we have to
do is define a set or oxidized
stain. These are stains that
require more than drycleaning
fluid, water or lubrication to
remove. Tannin, protein and oils
oxidize and set by picking up
oxygen from the air.
An example of oxidation is cutting an apple in half and watching it turn brown
from picking up
oxygen from the air. This is the theory behind invisible stains that show up
after a period of
Vegetable and cooking oils also oxidize by picking up oxygen from the air. These
from mineral oils such as Vaseline and motor oil which do not oxidize.
Paints and glues also oxidize after a period of time. We all know that a fresh
paint stain can be
simply washed off or drycleaned to remove.
There are several factors which produce oxidation and set stains, some of which
important than others. At the laboratories of Independent Garment Analysis, I
experiments concerning oxidation on various stains.
Age. The longer a stain remains in the fabric, the more oxidized and set it becomes.
means that a garment with older stains will be more difficult to remove than
fresh stains. The
extent to which a stain oxidizes due to age is a factor but not necessarily a
We stained several garments with vegetable oils, tannin and protein allowing it
to set in the
fabric for two weeks. Although the stains oxidized, it was not to an extent that
it could not be
Heat. This is a major factor in oxidization. We found that the heat of the spotting
improperly used caused oxidized and set stains. We found that placing mustard on
a fabric and
steaming it with the steam gun at close range causes the mustard to oxidize so
could remove it. When spotted properly without using excessive heat, the mustard
The same concept can be applied to vegetable oils. When vegetable oils splatter
on a fabric
from hot foods such as pizza and hot sauce, the stain was much more difficult to
oils used in salads.
Drycleaning. The drycleaning process often uses heat from 140°F to 150°F which can set
Pressing. The heat of pressing is one of the biggest factors causing stains to oxidize.
the reason why many vegetable oils on laundered shirts are most difficult to
when pressed on a hothead.
Fabrics. Wetside stains on natural fabrics such as wool, cotton, silk and linen will
oxidize to a
greater extent than on synthetic fibers such as polyester and nylon. Vegetable
oils oxidize to the
same extent on all fibers.
Chemicals. Certain chemicals can set stains, making them impossible to remove. For
example, when alcohol is put on a blood stain or other protein matter, the stain
in many cases
was impossible to remove.
Tannin stains such as coffee, tea, medicine and mustard will oxidize from
contact with alkali.
Put an alkali on a coffee stain or mustard and watch the stain change in color.
Avoiding oxidized stains
Pre-spotting. Light colored fabrics should be pre-spotted before drycleaning. Dark garments
usually do not have to be pre-spotted.
Spotting procedureto avoid oxidization
Flush area but keep steam gun six inches from fabric. If you can hold your hand
steam gun, it is the right distance.
Use mechanical action.
Flush (safe distance).
Flush (safe distance).
Any stain not removed at that point is oxidized and heat can be applied.
Oxalic Acid (test).
Rust remover (test).
Peroxide and ammonia (test).
Flush (safe distance from fabric).
Protein formula or digester.
Peroxide and ammonia.
Oily-type paint remover.
Oily type paint remover and amyl acetate.
Stains oxidized in cleaning, spotting