Records show that starch made from wheat was already used to stiffen clothing over 6,000 years ago in ancient Egypt. Not much has changed today. Commercial laundry starch is still made from plants and 80% of it is made from corn.
Initially dry powdered starch was used for laundry. The powder was mixed with luke-warm water and then spayed onto natural fabrics such as cotton or linen before ironing. Later on aerosol sprays were introduced. Although more costly, they are easier and more convenient to use.
The list of benefits of using starch is quite long. Most people value the crisp and stiffer feel it adds to a dress shirt (mostly on collars and cuffs). In addition using starch makes ironing much easier since: 1. the moisture it ads creates steam, and 2. it eliminated "ironing drag". Another thing worth mentioning is that starched dress shirts are more resistant to staining since the starch will prevent the stains to soak deep into the fabric.
There are only two small disadvantages of using starch. Fist of all using excessive starch can create discomfort and can irritate the skin. If you have sensitive skin it is recommended you use less starch and also wear an undershirt. A second disadvantage is that long term use of starch can shorten a garments lifetime. Starch builds up on collar and cuffs and it does dry out the fabric which can cause the fibers to fray and even break.
For more information you may also like to read our blog article on How to Starch Mens Dress Shirts.