Starch can increase the firmness of dress shirts and help them look more professional,
however it can shorten the overall life expectancy of shirts.
Shirts undergo two types of abrasions. Flat abrasion occurs when the shirt rubs against
another surface. Flex abrasion refers to the stretching of fibers when the wearer
bends an elbow or otherwise stretches the material.
Starch helps protect shirts by enabling them to withstand higher degrees of flat
abrasion. However, since starch stiffens the fibers and makes them less flexible,
it reduces the shirt's ability to withstand flex abrasion.
Dress shirts laundered without starch will still have a crisper finish than home
laundry, because the shirts are pressed while damp, with high temperature and pressure,
and are dried in the process. It is therefore a matter of taste if you want no,
light, medium or heavy starch.