Paint is no doubt one of the most stubborn stains. The very first thing that should be taken in notice is that what you were doing with paint in dress shirt. However, accidents happen and without wasting anymore time, you should start removing the paint from your dress shirt. The basic way of removing paint is same like removing general stains from shirt. There are two kinds of paints, water based paint and oil based paint. The key for completely removing paint form shirt is to act as quickly as you can. If you left the paint for half or full day, then it is expected that the paint will remain on your shirt forever, especially if it is oil based paint.
Let us get started with water-based paint, if the paint is still wet, remove the excess material with a knife. Soak the affected area into lukewarm water and smoothly blot it or use pressure water on affected area and let the water to remove the paint. If the paint is not removed completely from fibers of shirt then use a soft brush. If the water-based paint is dried up, it is still fixable, soak the affected area into warm water for a day or so and try the above-mentioned process. Water based paint stains are easy to remove, but oil based paint stains are quite difficult to remove.
If you get an oil-based paint on your shirt, instantly remove all the excess material with help of some sharp instrument. Soaking the affected area in water will not benefit, as oil has no effect of water over it. Similarly, none of the cleaning products will work on paint. The best way to remove oil-based paint is to use paint thinner. Dip the affected area in paint thinner and smoothly rubs the affected area. Then get a new thinner and again dip the area in to thinner and repeat the process. Then use dishwashing detergent, which will remove other remaining oil stains. In most cases oil based paint is easily removed with the help of thinner if the paint is wet. If the oil paint has totally dried up then there is no way you can completely remove the paint from your shirt in home, but trying commercial paint removers might help but not sure.