PHOTOGRAPHIC CORRESPONDENCE.
The Calotype Process: curling up of Paper.—I am happy in having the opportunity of replying to your correspondent C. E. F. (Vol. ix., p. 16.), because, with himself, I have found great annoyance from the curling up of some specimens of paper. In the papers recently sold as Turner's, I find this much increased upon his original make, so much so that, until I resorted to the following mode, I spoiled several sheets intended for negatives, by staining the back of the paper, and which thereby gave a difference of intensity when developed after exposure in the camera.
I have provided myself with some very thick extra white blotting-paper (procured of Sandford). This being thoroughly damped, and placed between two pieces of slate, remains so for many weeks. If the paper intended to be used is properly interleaved between this damp blotting-paper, and allowed to remain there twelve hours at least before it is to be iodized, it will be found to work most easily. It should be barely as damp as paper which is intended to be printed on.
This arrangement will be found exceedingly useful for damping evenly cardboard and printed positives when they are intended to be mounted, so as to ensure their perfect flatness.
It is quite immaterial whether the paper is floated on a solution or applied with a glass rod. If a very few sheets are to be manipulated upon, then, for economy, the glass rod is preferable; but if several, the floating has the advantage, because it ensures the most even application. I sent you a short paragraph (Vol. ix., p. 32.) showing how we may be deceived in water-marks upon paper; and when we are supposing ourselves to be using a paper of a particular date, in fact we are not doing so.
I would also caution your photographic correspondents from being deceived in the quality of a paper by the exceeding high gloss which is given it by extra hot-pressing. This is very pleasing to the eye, and would be a great advantage if the paper were to remain dry; but in the various washings and soakings which it undergoes in the several processes before the perfect picture is formed, the artificial surface is entirely removed, and it is only upon a paper of a natural firm and even make that favourable results will be procured.
H. W. Diamond.
Turner's Paper.—There is great difficulty in procuring good paper of Turner's make; he having lately undertaken a contract for Government in making paper for the new stamps, the manufacture of paper for photographic purposes has been to him of little importance. In fact, this observation, of the little importance of photographic compared to other papers, applies to all our great paper-makers, who have it in their power to make a suitable article. Mr. Towgood of St. Neots has been induced to manufacture a batch expressly for photography; but we regret to say that, although it is admirably adapted for albumenizing and printing positives, it is not favourable for iodizing, less so than his original make for ordinary purposes. All manufacturers, in order to please the eye, use bleaching materials, which deteriorate the paper chemically. They should be thoroughly impressed with the truth, that colour is of little consequence. A bad-coloured paper is of no importance; it is the extraneous substances in the paper itself which do the mischief.
Ed.
A Practical Photographic Query.—I have never had a practical lesson on photography. I have worked it out as far as I could myself, and I have derived much information in reading the pages of "N. & Q.," so that now I consider myself (although we are all apt to flatter ourselves) an average good manipulator. Independently of the information you have afforded me, I have read all the works upon photography which I could procure; and as the most extensive one is that by Mr. Robert Hunt, I went to the Exhibition of the Photographic Society just opened, thinking I might there see his works, and gain that information from an inspection of them which I desired. My disappointment was great on finding that Mr. Hunt does not exhibit, nor have I been able to see any of his specimens elsewhere. May I ask if Mr. Hunt ever attempts anything practically, or is it to the theory of photography alone that he directs his attention?
I begin to fear, unless he lets a little of each go hand-in-hand, that he will mislead some of us amateurs, although I am quite sure unintentionally; for personally I much respect him, having a high opinion of his scientific attainments.
A Reader of all Books on Photography.