How can I clean my mouldy slides or negatives?

The answer is VERY CAREFULLY!

Slides and negatives have been made in different ways by different manufacturers through out the last 100 years (or more). So we cannot recommend one sure-fire method. You need to get hold of a slide (or neg) that you consider dispensable - perhaps that one you accidentally took of your foot - and then experiment.

It is possible that warm soapy water will do the trick nicely, or if you are feeling more adventurous you might try glass cleaner (the blue stuff). If you are of a scientific bent you could try isopropyl alcohol, and if you have money to burn - no doubt your local photographic shop will have something "special" to do the trick.

Obviously you don't want to use anything abrasive. Don't squirt anything directly onto the celluloid, use a soft cloth (microfibre is good because it seems to leave less fluff - paper tissues are generally bad because they leave a lot of fluff).

Apply your chosen fluid to your chosen material and rub or wipe gently to remove the mould. If there is any grit on the celluloid you will scratch the surface - which is not good.

Points to note ...

• Mould normally only affects the matt side of the celluloid, so if there is no mould on the glossy side - don't touch it.
• Even if you remove all the surface mould, the image of the mould may remain on your image if the mould has eaten into the pigment.
• Although it can be risky, mouldy slides look terrible when they are scanned, so cleaning the mould off is generally worth the effort.