Usually the paper considered most excellent for copper-plate work is thick, tender, uniform paper, half-sized or not sized at all. It may be the same for lithography. However, it must not be supposed that good impressions cannot be obtained with sized paper. I have seen some that were as good as, and even better than, impressions made at the same time on unsized paper. Much depends on the dampening of the paper, on its make, and chiefly on the manner of sizing it. On the best sized English vellum paper, I have made blacker impressions than I could make on the best Swiss copper-plate printing-paper, so that I had to use fifty per cent less printing-color. On the contrary, in using an indubitably genuine English vellum paper with a bluish tinge, which had been sized only too well, I could not get good impressions despite all efforts. It was very hard to dampen also. Every sheet must be dampened singly, turned frequently and manipulated to smooth out the thousand irregularities that are caused by the moisture. Equally difficult to use were some sorts of genuine Holland paper, because they took color reluctantly. If, however, the correct degree of moisture is attained, if the paper takes it well, and, finally, if the color is right for it, it can be used with thorough success. I must mention a circumstance that may defeat all efforts of a beginner should he try to use a certain kind of paper which is very handsome, durable, very white, well sized, but a little rough and possessing an odor somewhat resembling honey as well as urine. Sometimes it is called _Kühnel_, and comes from a French factory. This paper has the property of depriving the stone of its preparation, and consequently to smut it. This paper can be used only for dry printing, where it does not require any dampening at all. It is said that this property of smutting the stone is due to the chemical bleaching. Others ascribe it to a peculiar kind of size. Perhaps it is both. The same defect is found in many sorts of colored papers if there is much alum in the coloring-matter, or if the tints are made from alkaline colors or those that contain soapy matter, or if it has been smoothed with soap. This, however, is readily understood after my explanation of the chemistry of the stone. IV DAMPENING THE PAPER Dry paper may be used for printing. In certain work it is necessary, in order not to spoil the paper. As a rule, however, paper is moistened in lithography as well as in other forms of printing, to make it softer and more receptive to the printing-color. After what I have said of chemical printing, it would seem that, as dampness is antagonistic to the reception of color, the moisture of the paper would hinder, rather than aid, printing. But experience proves the opposite. A damp paper takes color better than a dry one. But this is not because damp paper is an exception to the rule. On close study, we see that here, too, it only proves all that I said about the stone.