If you accidentally get a paint stain on your favorite jeans, don't be too upset.
Of course, you can always take your cherished item to the dry cleaner, but first try to deal with the stain yourself.
Oil paint
To get rid of a stain left by oil paint, you will have to use vegetable oil.
Soften the hardened paint with oil, then remove the residue from the fabric using a cotton pad and wash the jeans, having first removed the greasy stain with soap or powder.
Water-based paint
In this case, you can get rid of the contamination using such means as kerosene or gasoline.
If you are dealing with a light-colored fabric, you can also try acetone. If the stain is quite old, buy a bottle of white spirit.
Please note: all of the above may cause the paint to fade, so try them on an inconspicuous area first.