ady your the expert in your field of carpet cleaning, i've always refered to manuels in showing the customer the differences in carpet fibres & their construction & how they nap & can shad, if you have been on any carpet cleaning courses you are 9x out of 10 supplied with a manuel, i have found these extremely helpful in pre-qualifying of a job & i've found that the customer rarely questions the printed word. hope this is helpful, the customers complaint is refered to in most of the manuels that i have.