Lightening denim is a relatively straightforward process that can be accomplished in the comfort of your own home. Commonly known as stonewashing -- a description of the industry method -- lightening denim is achieved using some basic household items. The process leaves you with your own customised item of clothing as well as the rewarding sense that comes from making your own alterations. Personalising your denim can be achieved through a couple of methods, but combining them yields the strongest effect.
Fill a large basin or bucket with 8 to 10 inches of water (temperature is irrelevant), and put on a pair of rubber gloves.
Fill the cap from a bleach bottle a quarter full with bleach, and add it to the water. You will be able to add more bleach later, but start with a relatively small amount of bleach so you do not overdo it and lighten your denim too much.
Submerge your denim in the bleach and water mixture, and gently knead the denim, making sure that every part of it that you wish to lighten gets an equal amount of attention. Focus particularly on areas that you want to lighten more than others. Lay the denim out flat and wrinkle-free in the water and bleach in a bathtub for an even, all-over lightening.
Leave your denim to soak in the solution, checking back every 10 minutes or so to check the progress. Because it is wet, the denim will appear darker than after it has dried, so do not wait for the fabric to turn your desired level of lightness in the water. Remove it when it is half as light as you would like it to be, and wait for the denim to lighten as it dries.
Rinse the denim with cold water when you are happy with the lightening, and hang it out to dry. You can hang your denim outside without worrying about the effect of hanging it in direct sunlight.
Wash your finished denim with detergent and fabric softener in the washing machine to eradicate the harsh smell of bleach.
Repeat the lightening process if you are not happy with the end result until you have achieved the desired shade. Add more bleach when repeating the process if you found that a quarter cap was not sufficient the first time around -- for example, if your denim was only half as lightened as you wanted after 40 minutes soaking in a quarter of a cap, repeat the procedure like-for-like to bring it up to your fully desired level.
Put on the denim item as you would normally wear it.
Mark in pencil any specific areas that you want to lighten. Don't worry about this mark, as it will be erased by the sandpaper at a later stage. If you want to lighten the whole denim item, you don't need to make any marks. The most common spots that are lightened on a pair of jeans, for example, are the areas above the quadriceps, above the knees and below the waistline.
Remove the denim clothing, and lay it out on a flat, firm surface, such as a table or hardwood floor. Scratch away at the area that you wish to lighten with sandpaper, and continue rubbing firmly on this spot until you are satisfied with the lightening level. Periodically blow on the jeans to remove any excess denim that is being scratched away, as it may obscure your view of the denim and leave you unsure of how whitened it has become.
Focus the sandpaper only on the areas that you wish to lighten. This method allows you to have very specifically whitened areas on the denim, so it is preferable to the bleaching method if you are not looking for an all-over effect.
Wash the denim in the washing machine, and hang it out to dry. Repeat the sandpapering process if you are not satisfied with the end result.
Always exercise caution when using bleach. Read and follow the instructions on the bottle, and seek immediate medical attention if you ingest bleach or get some in your eyes. The lightening process cannot be undone, so do not overdo the lightening and risk ruining your favourite pair of jeans.