It's bound to happen sooner or later; you leave a pen in your pants pocket and it leaks all over the fabric, leaving an unsightly stain right on the front of your favorite pair. Fortunately, ink stains are relatively easy to remove, as long as the ink is water-based. This includes ink from ballpoint, gel and felt-tip pens.
Place a paper towel beneath the stained layer of fabric.
Soak another paper towel in rubbing alcohol and dab at the stained fabric. Do not rub. Repeat until you have lifted as much ink as you can. Replace both paper towels, top and bottom, as needed.
Rinse the stain well with water.
Rub laundry detergent into the stain. Let it stand several minutes.
Launder as usual.
Repeat each step again if the stain doesn't completely disappear after laundering. If the stain still hasn't vanished, place the pants in direct sunlight for a day. This will help bleach any remaining ink color.
The sooner you treat the stain, the easier it will be to remove.
You can also try spraying the stain with an alcohol-based hairspray.
For permanent ink stains, more effort may be required. Blot the stain with acetone-based nail polish remover until no more ink is lifted. Next, apply a spot stain remover, let stand several minutes and launder as usual. If, after laundering, the stain remains, soak it in milk or try rubbing it with a white (non-gel) toothpaste.