Supplies Chemical Products

Sizing agent (AKD)

A liquid product of synthetic origin (a dimer of the alkyl Ct).

It acts within the paper pulp as a gum ensuring the cellulose fibres are less absorbent. The average proportion used is 2% of the weight of the dry pulp.

It should be added directly to the paper pulp after refining or grinding and should be stirred into the pulp for some minutes.

Its pH neutral nature guarantees the conservation of the paper.

Description Price
250cc Bottle 6,20

Retention agent

Generally a cationic synthetic polymer. It acts as a bridge or link between cellulose fibres forming flakes which facilitate the elimination of water. In this way water used when sizing the paper is kept cleaner and the paper retains pigments, colorants and additives better.

Description Price
250cc Bottle



Calcium carbonate (CaCO3)

A mineral product in powder form.

Added to paper pulp (2%) as an alkaline reserve in order to prevent future acid attacks from the atmosphere. In larger doses it adds opacity, whiteness and improves the paper’s performance during printing.

Description Price
- Please ask

Carboxymethylcellulose (CMC)

A product obtained by modifying cellulose molecules, it is commercially available in granular form.

It is prepared by diluting the CMC in hot water, in a proportion of between 5 and 10%. Both as a surface treatment or mixed into the mixture, it has sizing and strengthening qualities.

Description Price
250cc Bottle 2,25


A product of animal origin. A collagen.

Animal-based gelatine has been used traditionally as a surface sizing agent to give paper durability and a barrier effect. It is sold in solid form and is prepared by diluting the gelatine in hot water and adding a small quantity of rock alum. The approximate proportions are 85% water, 10% gelatine and 0·5% of rock alum. It should be applied, while hot, to the surface of the dry paper.

Description Price
- Please ask

“Neri” polyethylene-oxide. PO

The Museum sells a synthetic “Neri” (polyethylene-oxide) in granular form.

It is used as a bonding agent in the making of paper with very long fibres; it increases the viscosity of the water allowing an improvement in sheet formation.

Using it, we can get thinner, more porous and transparent paper.

The best proportion is a teaspoon of PO to every 10 litres of water. It should be allowed to stand for some hours in order for the dispersion to become homogenous.

Description Price
100cc Bottle 16,50

Pigments for colouring

Colouring agents of organic, inorganic and synthetic origin. Comprising small particles which disperse in water and which can be easily applied to the pulp.

All of the colours are provided in liquid form and are pH neutral. They provide solid colours.

Pigments for colouring should be added to the pulp and stirred for a few minutes. We recommend applying a retention agent for better performance and to fix the colour to the fibre.

Description Price
Blue. 250cc Bottle 15,20
Grey. 250cc Bottle 10,50
Black. 250cc Bottle 8
Red. 250cc Bottle 17
Purple. 250cc Bottle 35