Re: How to measure the durability of a permanent marker?

Kameron,

As a Senior Scientist who works for Crayola, I have formulated marker inks 
for years.  You have chosen to do an excellent experiment.  You also have 
the right scientific method by using a control.  As for the treatments, 
you can either soak the shirts in the respective solutions or pretreat 
them with the solutions and put them all in the laundry.  Be forewarned, 
you must find a way to mark each shirt as consistently as possible (and 
realize that you may need more than one of the same color and brand of 
marker because coloring on fabric is hard on the marker tip and may damage 
it readily.  Consistency is obviously important here since more ink on one 
shirt versus another may skew the results of your study.  As for the 
evaluation, unfortunately, you do not have access to a spectrophotometer, 
which is what we use to measure color values of stains.  You will need to 
rely on a visual assessment (by eye) to ascertain if one solution was more 
effective than another.

Dr. Crayola