Paper & paper making, ancient and modern

by Richard Herring

The perfection, however, to which water-marks have now attained, which in many instances is really very beautiful, is owing to a more ingenious method recently patented, and since adopted by the Bank of England, as affording considerable protection to the public in determining the genuineness of a bank note.

For the original idea of producing light and shade, as seen in specimens 1, 13, and 15, we are indebted to Mr. Wm. Henry Smith, whose patient perseverance, and laborious efforts, at length enabled him to overcome many difficulties, and finally to produce not only any peculiarity of design, however complicate, but also to secure its repetition with a certainty of uniformity which, in the process of manufacture as hitherto conducted, it was found impossible to accomplish.

To produce a line water-mark of the character shown in specimens 10, 12, and 16, or of any of the autographs or crests in No. 14, (which sheet was produced from the mould which I employed at the London Institution,) we might either engrave the pattern or device first in some yielding surface, precisely as we should engrave a copper-plate for printing, and afterwards by immersing the plate in a solution of sulphate of copper, and electrotyping it in the usual way, allow the interstices of the engraving to give it as were a casting of pure copper, and thus an exact representation of the original device, which, upon being removed from the plate, and affixed to the surface of the wire-gauze forming the mould, would produce a corresponding impression in the paper: or, supposing perfect identity to be essential, as in the case of a bank note, we might engrave the design upon the surface of a steel die, taking care to cut those parts in the die deepest which are intended to give greater effect in the paper, and then, after having hardened, and otherwise properly prepared the die, it would be placed under a steam hammer or other stamping apparatus, for the purpose of producing what is technically termed a “force,” which is required to assist in transferring an impression from the die to a plate of sheet brass. This being done, the die, with the mould-plate in it, would next be taken to a perforating or cutting machine, where the back of the mould-plate—that is the portion which projects above the face of the die—would be removed, while that portion which was impressed into the design engraven, would remain untouched, and this being subsequently taken from the interstices of the die and placed in a frame upon a backing of fine wire-cloth, becomes a mould for the manufacture of paper of the pattern which is desired, or for the production of any water-mark, autograph, crest or device, however complicate.

Light and shade, as seen in Nos. 1, 13, and 15, are occasioned by a very similar process, but one which perhaps requires a little more care, and necessarily becomes somewhat more tedious. For instance, in the former case the pulp is distributed equally throughout the entire surface of the wire forming the mould, whereas now we have to contrive the means of increasing to a very great nicety the thickness or distribution of the pulp, and at the same time to make provision for the water’s draining away. This has been accomplished, as in the case of No. 13, by first taking an electrotype of the raised surface of any model or design, and again from that, forming in a similar manner a matrix or mould, both of which are subsequently mounted upon lead or gutta percha, in order that they may withstand the pressure which is required to be put upon them in giving impression to a sheet of very fine copper wire-gauze, which, in the form of a mould, and in the hands of the vatman, suffices ultimately to produce such beautiful transparent effects in paper pulp as those to which I have called your attention. By similar means a portrait of the Emperor Napoleon was produced for the Paris Exhibition.

The other specimens, 1 and 15, are produced in the same manner as the word “Five” in the centre of the new Bank of England note. The deepest shadows in the water-mark being occasioned by the deepest engraving upon the die, the lightest, by the shallowest, and so forth; the die being employed to give impression by means of the stamping press and “force” to the fine wire-gauze itself, which by this means, providing the die be properly cut, is accomplished far more successfully than by any other process, and with the additional advantage of securing perfect identity.

It may be interesting to call attention to the contrast as regards the method of mould-making originally practised, and that which has recently been adopted by the Bank of England. In a pair of five pound note moulds, prepared by the old process, there were 8 curved borders, 16 figures, 168 large waves, and 240 letters, which had all to be separately secured by the finest wire to the waved surface. There were 1,056 wires, 67,584 twists, and the same repetition where the stout wires were introduced to support the under surface. Therefore, with the backing, laying, large waves, figures, letters, and borders, before a pair of moulds was completed, there were some hundreds of thousands of stitches, most of which are now avoided by the new patent. But further, by this multitudinous stitching and sewing, the parts were never placed precisely in the same position, and the water-mark was consequently never identical. Now, the same die gives impression to the metal which transfers it to the water-mark, with a certainty of identity unattainable before, and one could almost say, never to be surpassed.

But, as it has been properly remarked, may we not detect principles in this process which are not only valuable to the Bank, but to all public establishments having important documents on paper, for what can exceed the value of such a test for discovering the deceptions of dishonest men. One’s signature, crest, or device of any kind, rendering the paper exclusively one’s own, can now be secured in a pair of moulds, at the cost merely of a few guineas.

Thus then, I have endeavoured briefly to glance at all the varied manipulations comprised in the term Paper Making; from the soiled rags, which by this regenerating process, are converted into pure and spotless paper, and thence to the operations which in degree distinguish it, until finally, the stronger the test for illuminating its perfection, but suffices to prove it of that most aristocratic class, to which belongs our new bank note.