Removing Mould Stains

Hello all! I was wondering whether there is anyone who could give me some practical advise on how to remove mould stains. It is the first time I have encountered this problem. This painting was covered in foam wrap and stored against a wall and the black background around the painted objects got full of mould. I have wiped the surface with a clean damp cloth more than once (using a new cloth every time), and put the painting in direct sunlight for a number of hours. What you see here are the stains. I have also wiped down this particular corner using cotton wool dipped in 70% rubbing alcohol diluted with water, but it was not effective.

Do you think that such stains could be removed? The painting is framed and varnished with Gamvar…and the board is an Ampersand Clayboard. The back was not affected. Any tips to salvage this work would be truly appreciated! Thanks for your time to read this.


Hi Christine, I have no experience with this but thought I would throw some ideas and theories in case they are useful… take them with a grain of salt :grin:.

Mould being a fungus can dig in with roots so getting rid of it can be tricky. Not sure if the discolouration is just those roots being left behind or from it damaging the paint surface itself… or maybe both. One option you might consider is removing the varnish and hoping that the mould never penetrated it and lifts?

If you end up repainting part of it (after removing the varnish) you should make sure to kill off the mould first if it is left behind. If you want to use natural products, look into a mix of vinegar and essential oils, but dampen the surface first (water or vinegar) so mould spores don’t get a chance to become airborne. Bleach is a bad idea as it doesn’t kill mould just hides it. Another option would be using a anti-fungal chemical. Now keep in mind I have no idea what these recommendations will do to the paint surface itself so I accept no responsibility :grin:.

Good luck.

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Hey Christine!

Unfortunately I haven’t run into this one before but apparaently it can be a big deal. Here’s an incredibly informative walkthrough of the issue for mold abatement from the University of Delaware MITRA MATERIALS INFORMATION & TECHNICAL RESOURCES FOR ARTISTS.


Hope this helps!

Hello Craig,

I would like to thank you for your input and for taking the time to help out :slight_smile: It is much appreciated. Apologies for my delay in getting back to you.

Since the alcohol and water solution did not help, the next step I went for is to remove the varnish and I was extremely happy to get this result (will post images below). It seems that the mould has not affected the board or paint layers as such, but those marks were on the varnish layer. I hope this has resolved it!! Since it never happened to me before I’m not sure whether the marks will eventually return or not……well hope not :blush:

Thanks again for your kind help.

Kind Regards,


Hello Anthony,

Thanks so much for these links. They are very helpful and have very useful info.

I removed the varnish layer and it seems to have solved the problem. I’m attaching before and after pics….and it seems that the marks were only on the varnish layer and the rest was not affected. Hope they won’t return!

Thanks again for your kind help. Much appreciated :slight_smile:

Kind Regards,


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Looks perfect!!! Glad to find some good info for you! <3