I had heard that the 4 oz bottles were originally a marketing gimmick. To give first time users a way to test the product. The paint has been very Popular, and is easy to use, in My personal experience. Now that the Shimrin line has been introduced, its good to see the small bottles returning. John Kosmoski the inventor of HOK was asked about the small quantity bottles, at a paint seminar that I attended in early October 2014, at the time John said he would ask Valspar to bring them back. It's nice to be able to buy a Cool color of paint, without the expense of buying a whole quart can.