HPMC (Hydroxypropyl Methylcellulose)
Definition
A water-reversible cellulose ether polymer used in dilute aqueous solution as an ink fixative; applied by atomiser to wet document surfaces to prevent ink migration during drying. Also used as a reversible consolidant in conservation practice.
Related terms
- Cockling
- The wavy planar distortion of a paper sheet caused by differential shrinkage between areas that dried at different rates, typically visible as...
- Controlled Air Drying
- Drying of a wet document flat on acid-free blotter at controlled temperature (18-20°C) and relative humidity (45-55%), separated from adjacent pages, with...
- Freeze-Drying (Vacuum Lyophilisation)
- A drying technique in which water is first frozen and then sublimed under reduced pressure (below 611 Pa), bypassing the liquid phase....
- Ink-Fixative Pretreatment
- Application of a dilute reversible polymer solution (HPMC, Cellugel) to the surface of a still-wet document before drying, forming a gel film...
- Mould Remediation
- The physical removal of established mould colonies from a document surface, typically by soft-bristle brush under HEPA-filtered vacuum; carried out when mould...
- Multispectral Imaging
- Photography or remote sensing in multiple wavelength bands beyond the visible spectrum, including near-infrared and short-wave infrared. Drone-mounted multispectral cameras are used...
- Saponin Treatment
- Application of a dilute aqueous saponin solution (a plant-derived surfactant) to a bloodstained document surface to reduce visible haemoglobin staining without significantly...
- Sequential Examination Protocol
- A formally agreed, documented inter-discipline sequence for examining a document that carries both handwriting or text evidence and biological evidence; the sequence...
- Tideline
- A concentrated deposit of dissolved ink chromophores, sizing agents, and mineral salts left at the advancing edge of a receding water front...
Explained in
- Water-Damaged, Wet and Stained Document RestorationA water-reversible cellulose ether polymer used in dilute aqueous solution as an ink fixative; applied by atomiser to wet document surfaces to prevent ink migr...