Some secrets of the silk trade.

The Living age 2132, 2.5.1882

From St. James's Gazette

Blue-books are not always dull; as witness the report of the Commission on Technical Instruction. Among other matters of general interest, its third volume contains an exhaustive little treatise on the English silk industry by Mr. Thomas Wardle. Of the suggestive historical details and the important statistics concerning the trade therein set forth we shall not now speak; our present purpose being to enlighten our readers on the subject of certain reprehensible practices of which they are the victims.

Dyeing is an important part of the production of silk goods; and it calls for great knowledge and ingenuity. But there is "another branch of dyeing quite as important as the tinctorial part of it" — a branch which is "not taught in the schools at present," and one which Mr. Wardle describes as "the scientific operation of weighing silk with adventitious matter." Mr. Wardle, however, is no apologist for these scientific operations, as may be inferred from their character.

Silk contains a gum or varnish to the amount of about one fourth of its weight. From silk intended for the warp of a black dyed fabric this gum is discharged by solution in boiling soap; the weight of each pound of silk being thus reduced to twelve ounces. To this residue of twelve ounces it has been an immemorial custom to add from one to four ounces of "weighting matter," so as to raise it as nearly to the original weight as may suit the manufacturer's intention as to the price and quality of the finished goods. This, be it observed, is what is done with threads intended for warps. But as the weft is mainly hidden by the warp threads, it need not be lustrous; so another method of dyeing is adopted; the gum or varnish is not boiled off, the silk being dyed "upon the gum," which easily absorbs weighting matter, the addition amounting to from four to eight ounces. A pound of silk so dyed would, therefore, return from the dyer weighing from twenty to twenty four ounces.

At first sight this seems a somewhat "shady" transaction; but then the color of black silk dyed without this weighting matter is not so permanent as with it. And for this reason: a good black — in fact, the best black — is formed in silk, as in ink, by the union of an iron salt and tannic acid. The acid has the property of amalgamating with the fibroin, or silk fibre; and of course by the union adds its weight to the weight of the silk. But blacks dyed without tannin are all more or less unstable; and "a good fast black, unweighted, and proof against light, acids, and alkalies, has yet to be discovered." Wherefore, if durability of color is wanted, an "unweighted black" is not to be recommended; and so far, "weighting," it is clear, is not only legitimate but necessary.

But it is clear also that the process opens the door to fraud; and, after a little hesitation, fraud walked in. Until 1857 blacks could not be dyed on "boiled-off" silks to a weight heavier than sixteen ounces per pound. One of those accidents, however, which often have so much to do with trade developments, led to a vast change. At that time what was called "Napoleon blue" was the fashionable color. It was (notwithstanding its name) a Prussian blue, produced in the usual way — i.e., by mordanting the silk with an iron salt, and then treating it with prussiate of potash. A variety of refinements and improvements in the method of dyeing this color appeared; the most important being the substitution of red for yellow prussiate of potash, and the addition to the iron salt bath of a solution of protochloride of tin; the result of which was a more substantial and brilliant blue. But what has all this to do with "weighted blacks"? More than seems, perhaps. For in a small Crefeld dye house, in 1857, a bank of silk that was to be dyed black got by accident into the prussiate and tin bath; and, on being passed into the dyebeck for black, was discovered to be of a black not only more lustrous and blue than the old process could produce, but was heavier, and through expansion of the fibres, bulkier into the bargain. Experiment confirmed the accident; the gain in weight was two ounces per pound over the old method, and henceforth blacks were dyed up to eighteen ounces to the pound.

But that was not the end of it. The new black proved more permanent than the old; it was taken up and developed to such an extent that nowadays French and German dyers have no difficulty, "by the use of tin, etc.," in increasing the weight up to forty ounces to the pound on the boiled silk, one hundred and twenty ounces per pound on unboiled, and even one hundred and fifty ounces per pound on spun silk. Now, says Mr. Wardle, there are two classes of goods, and always will be; and there are two classes of dyes, and always have been. That is to say, there are those goods and those dyes which must be durable, and those in which durability is unimportant. But the durable is the more costly; and the evil is that these heavily weighted and very perishable "silks" are being sold as pure silk, which is one of the most durable of products. The French and Germans have become so skilful in loading their silks, that fabrics that will not wear are made to look better than the old fashioned honest English ones that will; and, though costing less, they are sold often at more than twice as much as pure silk absolutely unweighted. Mr. Wardle gives an instance of what he says is a matter of every-day experience. The wife of a friend of his bought a dress in London, a black silk faille of French manufacture, for which she was charged 20s. per yard. In one short month "the fabric was completely disorganized" — "cut between sleeve and bodice, although it had only been worn a few times." Mr. Wardle found the warp of this dress weighted to twenty ounces and the weft to thirty two ounces per pound: the actual value of the fabric being 5s. 4d. a yard. Nor is the practice confined to black silks. Colored and white fabrics of all shades are now weighted to an enormous extent — are, in fact, so changed by the process as to be silk only in name; and nowhere is the practice carried on more unscrupulously than at Lyons.

Mr. Wardle fears that his full and frank exposure "will not be approved of by some English manufacturers, and by Continental manufacturers generally;" for it is vital to their business "to guard and keep secret all these falsifications, which are but little known outside the technical outforts." It is some satisfaction to learn, however, that not only the consumer, but also the merchant and the draper, are equally ignorant of the extent to which weighting is practised: the fraud is neither with them nor can it be detected by them. In appearance the weighted are quite equal to the unweighted silks; and all the technical skill and all the chemical knowledge of the Continental dyers are devoted less to perfecting the color than to increasing the weight and bulk of the silk entrusted to them.

Considering that France annually sends into London £9,000,000 worth of these loaded silks, and that Crefeld, to name only one German town, alone sends them to the yearly tune of £1,300,000 (immense quantities are also imported from Switzerland), it is obvious that we are being swindled on a considerable scale. Not that the plunder is always as large as in the instance quoted. According to Mr. Wardle, that is "an every day experience;" but it must be remembered that, while not a few are led to believe that goods they buy must be first-class when the price is high, many more are induced to buy when they are offered at cheaper prices than honest silk could be honestly sold for. In both cases, perhaps, neither kind of purchaser would buy at all if they knew what Mr. Wardle knows or what is here stated. Hee proposes to remedy a truly scandalous state of things by a law compelling every manufacturer, merchant, and draper to "declare" the material and amount of weighting when stating the price (as in one sense is already done by English dyers); and, in the case of imports, by heavily taxing the adulteration. On these points we offer no opinion; but we commend the whole question to ladies who buy silks, and to gentlemen who pay for them.