a luteola_, is an annual plant growing in waste places.
The whole plant is used for dyeing except the root. It is the best and
fastest of the yellow natural dyes.

The plant is gathered in June and July, it is then carefully dried in
the shade and tied up in bundles. When needed for dyeing it is broken
into pieces or chopped finely, the roots being discarded, and a
decoction is made by boiling it up in water for about 3/4 hour. It
gives a bright yellow with alum and tartar as mordant. With chrome it
yields an old gold shade; with tin it produces more orange coloured
yellows; with copper and iron, olive shades. The quantity of weld used
must be determined by the depth of colour required. Two per cent of
stannous chloride added to the mordant gives brilliancy and fastness
to the colour. Bright and fast orange yellows are got by mordanting
with 8 per cent stannous chloride instead of alum. With 6 per cent
copper sulphate and 8 per cent chalk, weld gives a good orange yellow.
Wool mordanted with 4 per cent of ferrous sulphate and 10 per cent
tartar and dyed in a separate bath with weld with 8 per cent chalk,
takes a good olive yellow. 8 per cent of alum is often used for
mordant for weld. A little chalk added to the dye bath makes the
colour more intense; common salt makes the colour richer and deeper.

Weld is of greater antiquity than most, if not all, other natural
yellow dyes. It is cultivated for dyeing in France, Germany and Italy.
It is important as it dyes silk with a fast colour.

(1) OLD GOLD

Mordant with 2 per cent chrome and dye with 60 per cent of weld in a
separate bath. 3 per cent chalk adds to intensity of colour.

(2) YELLOW

Mordant with alum, and dye with 1 lb. of weld for every pound of wool.
Common salt deepens the colour. If alum is added to the dye bath, the
colour becomes paler and more lively. Sulphate of iron inclines it to
brown.

(3) ORANGE

Mordant with alum with a little weld in the bath. Dye with weld. Add
teaspoonful of tin to the dye bath. Boil in separate bath with 1/4 oz.
madder or cochineal to the pound.

_OLD FUSTIC_

Fustic is the wood of _Morus tinctoria_, a tree of Central America. It
is used principally for wool. With Bichromate of Potash as mordant,
Old Fustic gives old gold colour. With alum it gives yellow, inclining
to lemon yellow. The brightest yellows are got from it by mordanting
with tin. With copper sulphate it yields olive colours (4 to 5 per
cent copper s