Chromic solution AL-3001 is very important step for the production of a good engraved screen. It is used to remove minor chock from the nickel screen. Chromic solution AL-3001 is scrubbed for 10-15 minutes on the nickel screen then screen is hosed down with water. it helps in reducing development time & it will not damage screens. chromic solution AL-3001 will be dark reddish.