From Longman Dictionary of Contemporary Englishspray-onˈspray-on adjective [only before noun]  a spray-on substance can be sprayed from a container onto a surface a spray-on water repellent for clothing
                                                    
                                                Examples from the Corpus
spray-on• You may wish to embellish the controls with rubdown lettering followed by a coat of spray-on protective lacquer as usual. 
