Whether a project goes awry or your pen explodes all over, ink can leave a dark and ugly mark. Most inks are even labeled permanent because they aren't made to be erased. Removing an ink stain from your carpet is tricky, but doable. Like most stains, the sooner you take action, the easier it will be to remove the stain.
Rubbing alcohol is your best bet for removing ink. Apply a generous amount of rubbing alcohol on a clean cloth and blot the ink stain repeatedly. It's extremely important to use pressure and blot the ink directly without smearing. If the ink smears, it becomes much more difficult to remove the stain, and you might end up needing a professional carpet cleaner. Start around the edges and work your way toward the middle, rewetting the cloth with more alcohol when necessary. Rubbing alcohol is safe to use on your carpet and the smell doesn't linger long.
If using any water-based mixture instead of rubbing alcohol, you’ll need to create a cleaning solution and use a spray bottle. Create a mixture of warm water and dishwashing soap and spray the ink stain until it's saturated. Blot the stain with a cloth and be sure not to scrub the stain. Then just as you did with the dish soap, mix one tablespoon of ammonia with a half cup of water. Spray this mixture on the stain as well, dabbing again without rubbing. Although the ink stain will be virtually gone after these first two steps, one more step is needed for a complete deep clean. Make a solution of equal parts water and vinegar. Spray the vinegar mixture on top of the area to clean up the ammonia and leave your carpet looking and smelling fresh and clean.