Bumpers are items that serve a utilitarian function on cars. They protect the more expensive sheet metal and engine components in case of minor crashes. Sometimes you may need to rechrome a bumper because it's been damaged or it's beginning to rust. Fortunately there are options for this, should it become necessary.
Use electro plating if you need to rechrome an entire bumper and desire it to be uniform. This involves a chemical bath and an electrical charge. Dissolve the chrome in the chemical bath and then place a cleaned and scoured bumper into the bath as well. An electrical current is run through the bath and as the current goes through the liquid, the dissolved chrome adheres to the bumper, creating a uniform sheet across the entire surface. This is the most expensive process for rechroming a bumper, but the best restoration process of a bumper's chrome.
For touch-ups, chrome paints are available that can be used to fix small problem areas on the bumper. These may only be made up of a small part of actual chrome, if there's any chrome at all, but the paints match the colour of the chrome that's already in place on the bumper. This process only works for chrome touch-ups and is not meant for an entire bumper.
Dipping is another option for rechroming a bumper. This isn't something that you can do at home, and it requires access to a lot of chrome metal as well as to the necessary tools to melt it. The bumper is lowered into a vat of chrome and then removed once it's been completely covered. This dipping process is used to coat a number of different items in metal, however it isn't as commonly used for chrome since electro plating works with so much less waste.