White shirt can be returned in different ways. The most common of them is the normal bleachsold in any Department store. In order to bleach the thing in this way, add the bleach when machine washing to washing powder. The dosage for each bleaching agent has its own. It is specified by the manufacturer. Not to spoil a thing, see maximum washing temperature on label.
You can use the grandmother's method. Boil shirt with the addition of "White". This method is highly effective. However, the fabric with such a rigorous whitening will quickly wear out.
You can bleach a shirt with "White", even without boiling it. To do this, simply add to hot water as indicated on the packaging of proportion. Keep the item in the solution only a couple of minutes. Then rinse thoroughly in warm water. Then again down into the solution. After a minute, remove and wash in the usual way.
Try the bleach thing with ammonia. Dissolve in hot water to five tablespoons of alcohol. On the half hour put the white shirt. After that rinse well.
In addition, a white shirt, you can quickly and easily bleached using hydrogen peroxide. 2 liters of water take one teaspoon of peroxide. For best results, add a pinch of soda ash. For 20 minutes place the white shirt in the resulting solution. Then remove it and wash it in the usual way.
Before using any chemical bleaching agents, carefully read the instructions for use. Otherwise you risk to spoil a white shirt.
All of these whitening methods can damage some synthetic fabrics. Therefore, in order not to spoil a thing, better take it to the dry cleaners.