What is a custom size golf flag? Basically if it is not a Master’s flag which is 13″ by 17″ or a PGA flag, U.S. Open or Ryder Cup which are 14″ by 20″ we usually refer to it as custom sized. Local club golf pin flags are often custom sized. Another advantage of using the custom code is that you have 5 different color mats to choose from: green, black, tan, white or navy. After watching the video come back and click here to view our custom golf flag frame options.