Dyeing Straw.

Scientific American 38, 9.6.1849

The French pursue a method of dyeing straw for hats, to open up when in a damp state and roll it our between a pair of cylinders. For light, delicate colors, this process is always pursued in new straw. To dye blue, common chemic (sulphate of indigo) to which has been added a little potash, is employed.

It will do very well, however, without the potash. This composition is used for various shades. A copper vessel is brought to boil and such a quantity of chemic added to the water, as will dye the shade desired, the fire is then removed and the straw put in and kept immersed until it is deep enough in shade. It is then taken out, washed in cold water and dried. This plan will dye the lightest and darkest shades of blue according tot he quantity of the sulphate of indigo used. Yellow color can be dyed on a straw by boiling it in a weak solution of yellow oak bark and alum, but the muriate of tin is better than the alum. Green can be dyed on straw by employing a bath of turmeric and a sulphate of indigo, but it is best to dye the straw yellow first with oak bark and then give it the sulphate of indigo, which should be neutralized of its acid by the sugar of lead. This makes a very fast green. Lilac may be dyed on straw, by first dyeing it a light blue and then a pink color on the top.

Pink is dyed by steeping the straw in a weak hot solution of cochineal and sulphuric acid, or instead of sulphuric, use the muriate of tin and some cream of tartar. This makes a very beautiful color.

Red colors may be dyed on straw by using a very strong solution of the cochineal and muriatic - no sulphuric acid. Every shade of drab on straws may be done in this way by using a greater or less depth of blue or pink on the straw, but it is best to dye the pink shade first and then dye the light blue on the top.

Fine reddish browns on straw are dyed with catechu, the sulphate of iron and the chromate of potash. The straw must be immersed in three separate vessels containing these three stuffs, commencing with the catechu. Wash the straw well when dyed before it is dried. Black is dyed on straw by a strong solution of hot logwood, into which the straw is steeped for about 10 hours. After this it is immersed in a weak solution of the sulphate of iron and sumac, and then washed and dried.

The above mores of dyeing straw will be found useful to many; and from the hints given, any person may branch out freely into all the shades, from gray to violet and deep brown.

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