While you may not notice an ink mark on a pair of dark denim jeans, it's practically impossible not to spot ink on khakis because of their light color. Instead of wondering whether it's time to dye the pants to match the ink, treat the stains with a few items you likely already have around the house, such as rubbing alcohol, or vinegar and cornstarch. The treatment methods are the same whether the ink is red, black or blue; it may take multiple attempts or more than one method to remove the ink completely, depending on the type of ink and how long it has been on the khakis. Wash the khakis in cold water after treating the stain, but be sure to check them thoroughly before placing them in the dryer to prevent heat-setting the ink.
Rubbing alcohol lifts ink out of many fabrics, including your favorite khakis. Place paper towels inside the khakis on the opposite side of the fabric beneath the stain, and then blot the area with rubbing alcohol applied to a paper towel or soft white cloth. Do not rub, because this may spread the ink. Continue blotting until no more ink comes up. Then turn the khakis inside out, repeating the process with more alcohol and paper towels. After you've removed the ink, wash the khakis as you normally would.
Hairspray or Hand Sanitizer
Either hairspray or hand sanitizer can be used to treat that ink stain in a pinch, if you aren't at home when the "oops" happens. Place paper towels on the underside of the fabric, if possible. Spray hairspray over the affected area, and then blot gently with plain paper towels. Do not rub the ink. If you use hand sanitizer, put a little sanitizer on your fingertip or a paper towel, and then blot it over the ink. Rub the ink gently from the outside of the stain toward the center; do not rub outward or the ink may spread. Pat excess sanitizer off the khakis afterward. If possible, wet the fabric in the affected area with cool water, and rub a little bar soap or liquid soap over the spot, again working from the outside of the stain toward the center. Rinse the area off or dab it with a damp paper towel if you're still wearing the khakis.
Sometimes, a soak in milk removes ink from fabric. Soak the inked part of your pants in a bowl of milk overnight; the ink should be gone or at least faded. Then wash the khakis as you normally would.
A gentle abrasive helps remove stubborn ink stains. Instead of reaching for sandpaper or a scrub brush, make a paste from baking soda and water, or vinegar and cornstarch. Dip your finger into the paste and rub it over the ink, working from the outside of the stain toward the center. Brush off the baking soda whenever it absorbs the ink, and reapply more of the paste until the ink is gone.