Again there are times when sheets are not cut quite square, which is, of course, inexcusably careless. Likewise, the packing of paper may be done in a careless manner, and cases too loosely packed, if set on end, often cause a wave in the paper, which sags in the case instead of remaining tight and flat. It is desirable that cases of paper be kept flat in storage and not set on end. Cases should be made from well-dried boards, and waterproof lining-paper should be used to exclude all dampness. When paper is finished in rolls it is fair to demand that the rolls should be wound evenly and hard, and all breaks should be carefully spliced and flagged. COLOR.--The foregoing troubles are mechanical. Other difficulties may exist, even when the paper is handled well on the machine, owing to errors in composition. The color may vary, and the term “color” includes the various shades called white, as well as tints. Color is affected by water conditions. In the case of mills which depends upon river water, the water sometimes becomes so dirty that it severely handicaps the paper-maker, in spite of his filtering apparatus, and at such times it becomes difficult to get as bright and lively shades as under favorable conditions. Dyestuffs do not always work uniformly, and, therefore, absolute matches of color from run to run are not to be expected. Shortcomings of this nature should be regarded with some lenience. In this class of difficulties, discrepancies in sizing are the less pardonable and are more apt to be noticed when hard sizing is requisite, as in writing-paper or index bristol. In such cases a lack of sufficient sizing is an incurable fault, for which the manufacturer is responsible. There are occasions when excess of sizing would be troublesome--for example, in a smooth-finished book-paper it would be likely to cause offsetting, but this trouble may be alleviated by using less ink, or, if necessary, by slip-sheeting. It would be difficult to catalogue all possible sources of trouble, but we have at least covered the principal defects of uncoated papers. PACKING.--Occasionally troubles may be charged to faulty packing--cases too loosely packed when stood on end permit the paper to sag, thus causing a curling tendency at one end of the sheets. The use of unseasoned case lumber or cases and inferior case lining give access to moisture, the effect of which is discussed herein at length. The susceptibility of coating to picking may be determined by applying hot sealing wax. If the wax after cooling is pulled off with only the coating adhering it may be assumed that a “tacky” ink would work the same, whereas if the paper tears out with the wax--it proves conclusively that the coating is well sized.