_COLOURED PAPERS._
Coloured Papers.--Colouring Matters used in Paper-Making.--
American Combinations for Colouring.--Mixing Colouring Materials
with Pulp.--Colouring Paper for Artificial Flowers.--Stains for
Glazed Papers.--Stains for Morocco Papers.--Stains for Satin
Papers.
=Coloured Papers.=--There are several methods by which any desired
shade of colour may be imparted to paper, which are as follows:--
1. By blending with the pulp in the beating-engine some insoluble
substance, such as smalts blue--a kind of glass coloured by oxide
of cobalt--ultramarine, yellow ochre, etc.
2. By adding a coloured liquid, which simply dyes or stains the
fibre.
3. By using rags which are already coloured, in proportions to
give the required shade, in which case of course the process of
bleaching must be omitted.
4. By employing two substances, as yellow prussiate of potash
(ferrocyanide of potassium) and a persalt of iron, for example,
which, when combined, yield the requisite blue tint--Prussian blue.
By this latter method the buff shade given to what is termed
_toned paper_ is effected, by using a solution of copperas
(sulphate of iron) and an alkaline solution, or by using a solution
of pernitrate of iron. In experimenting in this direction we
have found that a mixture of solutions of sulphate of iron and
bichromate of potassa produce an agreeable and permanent buff tint.
The solutions may be added to the pulp alternately, or may be first
mixed and then at once put into the beater. From 2 to 3 ozs. of
each salt for each gallon of water may be used if the solutions are
to be mixed before using; but when applied separately the solutions
may be used in a more concentrated condition.
=Colouring Matters used in Paper-Making.=--The following
substances, used either alone or mixed in suitable proportions, are
employed in colouring pulp for paper-making:--
Smalts blue.
Prussian blue.
Indigo blue.
Aniline blues.
Aniline reds, including eosine.
Cochineal, for pink, etc.
Brazil wood, which imparts either a fine red or orange-brown
colour, according to the treatment it has undergone.
Logwood, for violet colours.
Chrome yellow and orange chrome.
Orange mineral.
Copperas, for mixing with other substances.
Venetian red.
Yellow ochre.
Quercitron, or oak-bark.
Nutgalls.
Lamp black.
_Blue._--The coarser kind of paper used for packing is prepared
from rags blued with indigo, which, when reduced to pulp, are
not subjected to the process of bleaching. The finer kinds of
paper are blued in various ways, but the chief material used is
what is known as artificial ultramarine, of which there are many
qualities in the market, to which reference is made in another
chapter. Prussian blue is also used, but this is usually produced
directly in the beating-engine by adding in solution, 95 parts
of sulphate of iron and 100 parts of ferrocyanide of potassium
(yellow prussiate of potash). Smalts blue, which was formerly much
used before the introduction of artificial ultramarine, is still
preferred for high-classed papers as the colour is more permanent.
To obtain smalts in an exceedingly fine state of division the best
plan is to grind the colour in a little water, and then to separate
the finest particle by the process of _elutriation_, that is, by
diffusing the reduced mass through a large volume of water, and
after allowing the larger particles to subside, pouring off the
liquor in which the finer particles are suspended, to a separate
vessel, in which they are allowed to subside. If this operation is
carefully conducted the smalts may be obtained in an exceedingly
fine state of division, and we have found that in this state the
colour blends well with the pulp, and has little or no disposition
to sink through it, but produces a uniform colouring throughout.
=American Combinations for Colouring.=--Hofmann gives the following
examples of the combination of colours which have been adopted by
American manufacturers:--
_Yellow Gold Envelope_ of fine quality is made of--
Bichromate of potash 10 lbs.
Nitrate of lead 18 "
Orange mineral 56 "
Porous alum 30 "
each substance being separately dissolved and added to 400 lbs. of
pulp.
_Orange-red Gold Envelope_:--
Bichromate of potash 7 lbs.
Nitrate of lead 10½ "
Orange mineral 60 "
Porous alum 20 "
These substances are dissolved separately and added to 400 lbs. of
pulp.
_Buff Envelope_ of fine deep shade is made from--
Bichromate of potash 3 lbs.
Nitrate of lead 5 "
Orange mineral 10 "
American ochre 20 "
Porous alum 30 "
Some half-stuff of red jute bagging. For 400 lbs. of pulp.
_Tea-Colour_ is made from a decoction of quercitron bark, the
liquid being poured into the engine, and 2 lbs. of copperas in
solution are added for every gallon of the bark extract. A little
ultramarine may be used to brighten the colour.
_Drab._--Venetian red, well washed, added to a pulp of tea-colour
made as above will give a fine drab.
_Brown_ is composed of several colours, or a very fine dark green
tea-colour brown, containing tea, buff, drab, and ink-grey, may be
made of--
Quercitron bark liquid 15 gals.
Bicarbonate of soda 2 lbs.
Venetian red 4 "
Extract of nutgalls 2½ "
Copperas 18 "
Porous alum 30 "
The above proportions are for 400 lbs. of pulp.
The large proportion of alum prescribed in all the above examples
serves as a mordant, and also, with the addition of resin soap, for
sizing. All the above mixtures should be passed through a No. 60
wire-cloth into the beating-engine.
=Mixing Colouring Materials with Pulp.=--It will be readily
understood that when paper is sized in the pulp, as Mr. Hofmann
points out, the resinous alumina surrounds the fibres and prevents
the colouring materials from penetrating them. In such cases the
colouring materials are only loosely held, and a portion must
therefore be lost in the machine. If added to the pulp before it is
sized they become thoroughly mixed with the fibres, and with them
enveloped by the size. The pulp should always be coloured before it
is sized, except in cases where the alum or resin soap would injure
the colours, or be injured by them. While the pulp is being sized
and coloured, the finishing touch is given by the engine-man, who
examines it and empties it into the stuff-chest.
=Colouring Paper for Artificial Flowers.=--Davis gives the
following recipes for colouring one ream of paper of medium weight
and size, sap colours only being used, and principally those
containing much colouring matter. The gum arabic given in the
recipes is dissolved in the sap-liquor.
_Blue_ (dark) 1.--Mix 1 gallon of tincture of Berlin blue with
2 ozs. each of wax soap and gum tragacanth. 2. Mix ¾ gallon of
tincture of Berlin blue with 2 ozs. of wax soap, and 4¼ ozs. of gum
tragacanth.
_Crimson._--Mix 1 gallon of liquor of Brazil wood compounded with
borax, 2 ozs. wax soap and 8¾ ozs. of gum arabic.
_Green._--1. Take ½ gallon of liquor of sap-green[28], 4¼ ozs.
of indigo rubbed up fine, 1 oz. of wax soap, and 4½ ozs. of gum
arabic. 2. ½ gallon of sap-green liquor, 4¼ ozs. of distilled
verdigris, 1 oz. of wax soap, and 4½ ozs. of gum arabic.
_Yellow_ (golden).--Mix 6½ ozs. of gamboge with 2 ozs. of wax soap.
_Yellow_ (lemon).--1. Compound 1 gallon of juice of Persian berries
with 2 ozs. of wax soap and 8¾ ozs. of gum arabic. 2. Add to 1
gallon of quercitron liquor, compounded with solution of tin, 2
ozs. of wax soap, and 8¾ ozs. of gum arabic.
_Yellow_ (pale).--Mix 1 gallon of fustic, 2 ozs. of wax soap, and
8¾ ozs. gum arabic.
_Yellow_ (green).--Compound 1 gallon of sap-green liquor with 2
ozs. each of distilled verdigris and wax soap, and 8¾ ozs. of gum
arabic.
_Red_ (dark).--1 gallon of Brazil-wood liquor, 2 ozs. of wax soap,
and 8¾ ozs. of gum arabic.
_Rose Colour._--Mix 1 gallon of cochineal liquor with 2 ozs. of wax
soap, and 8¾ ozs. of gum arabic.
_Scarlet._--1. Mix 1 gallon of Brazil wood liquor compounded with
alum and a solution of copper, with 2 ozs. of wax soap, and 8¾ ozs.
of gum arabic. 2. Mix 1 gallon of cochineal liquor compounded with
citrate of tin, with 2 ozs. of wax soap, and 8¾ ozs. of gum arabic.
=Stains for Glazed Papers.=--Owing to the cheapness of these
papers glue is used in lieu of the more expensive gums; 1 lb. of
glue dissolved in 1¼ gallon of water; the proportions of colouring
materials are given for 1 ream of paper of medium weight and size.
_Black._--1. Dissolve 1 lb. of glue in 1¼ gallon of water;
triturate this with lampblack (1 lb.) previously rubbed up in rye
whiskey; Frankfort black, 2¾ lbs.; Paris blue, 2 ozs.; wax soap, 1
oz.; then add liquor of logwood, 1½ lb. 2. 1½ gallon of liquor of
logwood compounded with sulphate of iron, 1 oz. of wax soap, and 4½
ozs. of gum arabic.
_Blue_ (azure).--1¼ gallon of glue liquor, as before, mixed with 1½
lb. Berlin blue, 2¾ lbs. powdered chalk, 2¼ ozs. of light mineral
blue, and 2 ozs. of wax soap.
_Blue_ (dark).--Mix with 1¼ gallon of glue liquor, 4½ lbs. of
powdered chalk, 4¼ ozs. of Paris blue, and 2 ozs. of wax soap.
_Blue_ (pale).--1. Mix ½ gallon of tincture of Berlin blue and 1
oz. of wax soap with 3½ ozs. of solution of gum tragacanth. 2. Take
1¼ gallon of glue liquor and mix with 4 lbs. of powdered chalk and
2 ozs. each of Paris blue and wax soap.
_Brown_ (dark).--1. 1¼ gallon of glue liquor, mixed with 6 lbs.
each of colcothar (jewellers' rouge) and English pink, 1½ lb. of
powdered chalk, and 2 ozs. of wax soap. 2. Dissolve 1 oz. of wax
soap and 4½ ozs. of gum arabic in ½ gallon of good Brazil-wood
liquor, and add a like quantity of tincture of gallnuts.
_Green_ (copper).--Mix in 1¼ gallon of glue liquor 4 lbs. of
English verdigris, 1½ lb. of powdered chalk, and 4 ozs. of wax soap.
_Green_ (pale).--Mix with 1¼ gallon of glue liquor 1 lb. of Bremen
blue, 8½ ozs. of whiting, 1 oz. of pale chrome yellow, and 2 ozs.
of wax soap.
_Lemon Colour._--Mix in 1¼ gallon of glue liquor 13 ozs. of lemon
chrome, 2 lbs. of powdered chalk, and 2 ozs. of wax soap.
_Orange-Yellow._--Mix in 1¼ gallon of glue liquor 2 lbs. of lemon
chrome, 1 lb. of Turkish minium, 2 lbs. of white lead, and 2 ozs.
of wax soap.
_Red_ (cherry).--Mix in 1¼ gallon of glue liquor 8½ lbs. of Turkey
red, previously mixed up with ¼ gallon of Brazil-wood liquor, and 2
ozs. of wax soap.
_Red_ (dark).--Mix ¾ gallon of Brazil-wood liquor with wax soap 1
oz., and gum arabic 4½ ozs.
_Red_ (pale).--To 1¼ gallon of glue liquor is to be added 8¼ lbs.
of Turkey red previously rubbed up with 2 ozs. of wax soap.
_Violet._--4½ ozs. of gum arabic, and 1 oz. of wax soap are to
be mixed with ½ gallon of good logwood liquor. When the gum is
dissolved, mix with it enough potash to form a mordant.
=Stains for Morocco Papers.=--For 1 ream of paper of medium size
and weight the following recipes are recommended:--
_Black._--8¾ ozs. of good parchment shavings are dissolved in 1½
gallon of water; into this liquid is to be stirred lampblack, 1
lb., Frankfort black, 3 lbs., and Paris blue, 1¾ oz.
_Blue_ (dark).--Dissolve parchment shavings, as before, and mix in
8¼ lbs. of white lead and 4½ lbs. of Paris blue.
_Blue_ (light).--Dissolve parchment shavings, as before, and mix in
8¾ lbs. of white lead and 2¼ ozs. of Paris blue.
_Green_ (dark).--Dissolve 13 ozs. of parchment shavings in 2½
gallons of water, and mix in 10 lbs. of Schweinfurth green.
_Green_ (pale).--Prepare solution of parchment as in the last, and
mix with 8¾ lbs. of Schweinfurth green and 1 lb. of fine Paris blue.
_Orange-Yellow._--8¾ ozs. of parchment shavings are to be dissolved
in 1½ gallon of water, and then mixed with 1½ lb. of lemon chrome,
8¾ ozs. of orange chrome, and 1 lb. of white lead.
_Red_ (dark).--To the same quantity of parchment liquor as the last
is to be added 7¾ lbs. of fine cinnabar, and 1 lb. of Turkey red.
_Red_ (pale).--To the same quantity of parchment liquor add 8¾ ozs.
of Turkey red.
_Violet_ (light).--To 1½ gallon of parchment liquor add 4¼ lbs. of
white lead, 13 ozs. of light mineral blue, and 8¾ ozs. of scarlet
lake.
_Violet_ (dark).--To 1½ gallon of parchment liquor add 3¾ lbs. of
white lead, 1 lb. of pale mineral blue, and 8¾ ozs. of scarlet lake.
_Yellow_ (pale).--To 1½ gallon of parchment liquor add 2 lbs. of
light chrome yellow and 8¾ ozs. of white lead.
=Stains for Satin Papers.=--For each ream of paper of medium weight
and size the following recipes are given:--
_Blue_ (azure).--13 ozs. of parchment are dissolved in 2½ gallons
of water and mixed with 3 lbs. of Bremen blue, 1¾ lb. of English
mineral blue, and 4½ ozs. of wax soap.
_Blue_ (light).--8¾ ozs. of parchment are to be dissolved in 1½
gallon of water, and to be mixed with light chrome yellow, 13 ozs.;
colcothar, 6½ ozs.; Frankfort black, 2 ozs.; powdered chalk 3 lbs.,
and wax soap, 3½ ozs.
_Brown_ (reddish).--1½ gallon of parchment liquor as the last, to
which is added yellow ochre, 1 lb.; light chrome yellow, 4½ ozs.;
white lead, 1 lb.; red ochre, 1 oz., and wax soap, 3½ ozs.
_Brown_ (light).--1½ gallon of parchment liquor, as before,
to which is added 13 ozs. of light chrome yellow, 6½ ozs. of
colcothar, 2 ozs. of Frankfort black, 3 lbs. of powdered chalk, and
3½ ozs. of wax soap.
_Grey_ (light).--1½ gallon of parchment liquor is mixed with 4¼
lbs. of powdered chalk, 8¾ ozs. of Frankfort black, 1 oz. of Paris
blue, and 3½ ozs. of wax soap.
_Grey_ (bluish).--To the above quantity of parchment liquor add 4¼
lbs. of powdered chalk, 1 lb. of light mineral blue, 4¼ ozs. of
English green, 1¾ oz. of Frankfort black, and 3½ ozs. of wax soap.
_Green_ (brownish).--To the same quantity of parchment liquor add
Schweinfurth green, 1 lb.; mineral green, 8¾ ozs.; burnt umber and
English pink, of each 4¼ ozs.; whiting, 1 lb., and wax soap, 3½ ozs.
_Green_ (light).--To the same quantity of parchment liquor add
English green and powdered chalk, of each 2¾ lbs., and 3½ ozs. of
wax soap.
_Lemon Colour._--To the same quantity of parchment liquor add lemon
chrome, 1½ lb.; white lead 1 lb., and wax soap, 3½ ozs.
_Orange-Yellow._--Parchment liquor as before, 1½ gallon, to which
is added lemon chrome, 4¼ lbs.; Turkey red, 8¾ ozs.; white lead, 1
lb., and wax soap, 3½ ozs.
_Rose Colour._--1½ gallon of parchment liquor as before, to which
is added ¾ gallon of rose colour prepared from Brazil wood and
chalk, and 6½ lbs. of wax soap.
_Violet_ (light).--1½ gallon of parchment liquor as above, mixed
with light mineral blue and scarlet lake, of each 1½ lb.; white
lead, 1 lb., and wax soap, 3½ ozs.
_White._--To 1½ gallons of parchment liquor is added fine Kremnitz
white, 8¾ lbs., Bremen blue, 4¼ ozs., and wax soap, 3½ ozs.
_Silver White._--1½ gallon of parchment liquor mixed with Kremnitz
white, 8¾ lbs., Frankfort black, 8¾ ozs., and wax soap, 3½ ozs.
_Pale Yellow._--1½ gallon of parchment liquor, to which is added 4½
lbs. of light chrome yellow, 1 lb. of powdered chalk, and 3½ ozs.
of wax soap.