well it is usally up to the contractor in reguards to what you want to do. you also need to factor that into the quote (obviously). However, we just make sure there isn’t really any heavy debris around the lines.(sweep and hand blow) this debris can greatly affect the quality of the line, like paint splattering and hourglassing. A little dust isnt that bad, but hitting rocks while you paint lines is never fun aswell as striping over dirt! You may also like to mention cleaning of the entire lot to the customer if it is really bad. some people dont really care, but you should show them you do. Good luck.
