During mould growth, digestive enzymes cause weakening of the surface. This can impact significantly on the condition of a document and lead to irreversible damage, including:
- Adhesion and/or blocking – through the addition of moisture, pages are stuck together and cannot be turned or separated easily (fig. 9-10), leading to loss of information
- Breakdown in mechanical strength of substrate – a document becomes difficult to handle without causing further damage (fig. 11-12)
- Losses – where significant portions of a document have been detached or completely dissociated (fig. 13-14), leading to loss of information
![An original paper manuscript, with a page lifted up to show the damage between the pages. They are greyed and deteriorating severely at the edges. Severe discolouration can also be seen.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Fig.-9-–-E-190-5-4-Identification.png)
Figure 9 – E 190/5/4
![A close-up of the original manuscript that appears in Figure 9. The greyed and deteriorating top edge of the document can be seen, as a gloves hand uses a thin tool to prise two pages apart.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Fig.-10-–-E-190-5-4.jpg)
Figure 10 – E 190/5/4
![A corner of an original manuscript, showing holes in the paper caused by mould damage.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Figure-11-–-C-101-1246-Identification.png)
Figure 11 – C 101/1246
![A corner of what appears to be a land survey, showing discolouration and deterioration of the edges.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Figure-12-–-IR-58-21229-Identification.jpg)
Figure 12 – IR 58/21229
![An ornately written manuscript roll, displaying crisping at the edges, a rust brown stain down the middle-right of the document, and holes in the paper. A small detached piece of the document can also be seen, placed on top of the roll.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Figure-13-SC-CHARLESI-1703-1705-Identification-1024x768.jpg)
Figure 13 – SC 6/CHARLESI/1703/1705
![An original handwritten and tabulated record. Holes in the document and deterioration of the edges is very apparent.](https://www.nationalarchives.gov.uk/wp-content/uploads/sites/23/2024/05/Figure-14-–-E-190-585-21-Identification-e1714745614571.jpg)
Figure 14 – E 190/585/21
For further information on the ecology of mould, please refer to [hyperlink to Ecology of Mould pages]