Pigment inks, fixing

In very stubborn cases, another treatment is used. Inks and pigments are fixed and the artifact is immersed in a bath of polyethylene glycol (PEG 400). An entire codex can be placed in two or three large plastic tubs and kept there until the parchment is soft and pliable. This procedure can take days or weeks. The parchment is removed and blotted and pressed in the same manner as the treatment in ethanol and water. If the parchment becomes translucent while in the bath, the phenomenon will disappear with the blotting and pressing process. 

Pigment inks are used on cellulose fibers and often protein fibers and nylon. Particles of pigment are fixed by a film of binder that traps all of the dye molecules so that there is usually no need to wash out any excess. While washing may not be necessary after pigment fixation, it may be preferable for the consumer, particularly if it can soften the stiffer handle that tends to occur with pigment printing. 

Transparent white pigments (extenders) commonly used in inks, in order of decreasing transparency, ate alumina hydrate, magnesium carbonate, calcium carbonate, blanc fixe (precipitated barium sulfate), talc, and clay. Extenders ate sometimes used to reduce the color strength and change the theology of inks. 

Potassium chromate (K CrO ) is soluble in water and is used to make bright yellow inks and paint pigments. It is also used as a reagent in chemical laboratories and as a mordant to fix dyes in colored textiles. 

Chemistry, Physics, and Biology Laboratories. As a rule, before any artifact is subjected to treatment, the chemistry laboratory determines the causes of any alterations or deterioration. The nature and structure of the artifact, its pigments and inks, are identified to avoid negative reactions to prescribed treatment. Fixatives are recommended if required these may be cellulose acetate dissolved in acetone, soluble nylon, or acrylic resin sprays. Once stains are identified, several possible solvents are selected. For deacidification, either magnesium bicarbonate or barium hydroxide usually is recommended, depending on whether an aqueous or nonaqueous solution is called for. Bleaching is discouraged, but when necessary, hypochlorites are used with suitable antichlors. 

Parchment Shop. There are five restorers in this shop. Parchment documents and book covers to be restored get a mechanical surface cleaning with soft erasers then harder ones, if required, to remove dirt and grime. Hard, embrittled, and dry artifacts have their inks and pigments fixed with an acrylic resin spray or with a fine brush dipped in paraloid before immersion in a bath of ethanol and water (70% and 30%, respectively). 

Atra Polymer 10. [Atramax] Ammonium carboxylate, styrene cqxdymer film-farming dispersant fix pigments vdiicle for flexo ink. 

BASF ADudi Blue . [BASF AG] Cone, pigment pastes with tripbenylmedume p menis fix inks, typewriter ribbon inks, carbon paper. 

In some instances, the pigment is carbon black directly suspended in a high boiling point aliphatic hydrocarbon solution. This ink has no binder but instead is fixed to the paper by diffusion of the oil into the paper thus leaving a highly blackened layer of carbon black and oil upon the surface of the paper. 

Barytes lbar- It, ber- See also blanc fixe. Natural barium sulphate used as an ink pigment and a white extender. It is considerably more abrasive and gritty than precipitated barium sulphate See image). 

Gloss white n. A white mineral pigment used as an ink extender, made by co-precipitation of alumina hydrate and blanc fixe. 

A resin emulsion can be added for improving the fixing properties of a pigment in the ink to form images such as letters and figures with an excellent in rub resistance. In order to secure the stability of the dispersion, an emulsion made from an alkyl(meth)acrylate or an aromatic vinyl compound is used. The preparation of such an emulsion is detailed below (18). 

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