ASSOCIATIONS OF LUMBER MANUFACTURERS The more important of the associations of lumber manufacturers, together with their headquarters and the woods with which they deal, are given on page 38. In addition to setting standards for lumber grades and sizes, these associations are valuable sources of information upon trade customs and the uses of lumber. They are not selling organizations; but an inquiry directed to them will promptly bring a reply stating where and of whom any given product may be purchased. Several of the associations conduct extensive advertising campaigns to increase the demand for their products; and from them the prospective timber user may obtain a great deal of interesting information put up in attractive form, as well as samples of the various woods, from which their quality and structure may be judged.