In the last year of volunteering at the National Trust house Anglesey Abbey I have started getting involved in book cleaning. The library at the Abbey is vast and the house so busy they only get cleaned every few years, so on top of collecting dust from all of the visitors who pass through, they can also be at risk from pests making a home on the shelves, light damage from the sun coming in the windows and the temperature of the room, which can affect whether or not a book develops mould (once that happens you drop everything and run).
While I’ve been lucky enough to avoid encountering mould in the books I’ve cleaned, there are some areas of the house where the conditions of the room have created a ‘micro climate’ wherein the affected books have been closed off with moisture and warmth; from then on if one book develops mould, soon enough they all will.
The process of cleaning un-mouldy books though is fairly methodical. In a team of two or three people, you carefully remove the books from the shelves (remembering their order); after filling in a form of the books details and checking it for loose/ripped pages or any other hazards, you bring it to a table where a box has been fitted on its side, open end towards you, with a vacuum cleaner hose attached through a hole in the bottom. This will catch any of the dust you brush off so that you’re not spreading it around. You use one brush to clean the outside, another brush to clean the inside, with smooth strokes towards the box – making sure to get the top edge of the pages, this is where most dust collects. Inside the book you need only do a few of the first and last pages, and wherever the book opens naturally, the dust wouldn’t have gotten in to the other pages.
Beyond an interesting book with unexpected topics, illustrations and annotations, the most likely thing you’ll find in a book is fading from light damage, page discolouration and foxing. Unfortunately, these cannot be treated, only prevented. So if you want to preserve your book for years to come, be sure to never read it, wrap it up tight in acid-free paper, lock it in a box and keep it under your bed. Sorted.
The conservation-wiki says about Foxing :
High humidity and damp conditions are the main causes of foxing. Due to the metal in papermaking machines, iron in the water source, dirt or pollution, there may be traces of metal dispersed among the paper fibers. When the paper absorbs moisture, the metal traces begin to oxidize in those areas, causing disintegration and discoloration. This creates an acidic environment, which also encourages mold growth. Mold will also feed on the paper itself as well as any organic materials on the paper such as dirt, finger marks, food stains, or insects.