acetone
Acetone is the basic ingredient of nail polish removers, but some removers also contain such substances, which can make it difficult, and even make it impossible to remove the stain. Diluted acetone removes pen and cement marks well.
The dirty part should be stretched on a backing made of absorbent material, pour a few drops of acetone over it and gently scrape off the dissolved dirt with a grease knife. The backing must be replaced, when it becomes colored, then repeat the process.
Then the dirty place should be rubbed with powder detergent and rinsed with cold water. If the residual stains do not disappear, all clothing must be washed in color bleach, if marked on the tag, that it is safe for the fabric.
Precautions: flammable and toxic. Do not use on acetate fibers. Perform a test before use.
Where to buy: chemical stores.