I use a Rowney Stay-wet acrylic palette but in a very short period of time the semi-permeable membrane and reservoir papers develop spots of black mould. I have to scrap any paint that is stored on them and start again, I've tried sterilizing the plastic tray with a bleach solution but the mould still eventually comes back when I replace the papers.

The technical division of Daler-Rowney say that this is a problem they have come across and although in laboratory tests they haven't found the mould occurring on the palette in less than a month, they cannot guarantee it staying mould-free for more than seven days, since conditions vary from one environment to another. Reduce the risk by using water from the cold tap rather than that stored in the hot tank. Sterilized water may make the problem worse since it doesn't contain the chlorine and minerals of tap water. Store your palette in a cold place - condensation helps mould to multiply fast. Although mould doesn't look very nice, since acrylic paints contain preservatives your painting shouldn't be affected in any way by using the stored paint. However, perhaps the best thing to do is to use small amounts of paint and avoid having to store it for too long on the palette.

I had experienced the same problems with both Rowney and Windsor & Newton stay wet pallets, however I have been using Milton sterilzsing fluid for a while now. The stuff that is used to sterilize babys milk bottles. Guess what no more dreaded black spots. I mix a teaspoon of Milton fluid with a mug of cold water and use that to wet down the blotting paper, and then top this up whenever the paper starts to dry out, I also leave plain water in the brush holder on the W&N model, this seems to help keep the pallet damp for longer when the lid is replaced. So far i have not noticed any changes in the way the paint behaves or dries out on the canvas or paper, so I guess its safe. I have used it with atelier, rowney and w&n artists acrylics, SAA and Cryla "Flow" acylics.

I don't use a palet, unless you call a plastic lid from an ice cream box a palet! I'm not into this stay wet stuff, and I manage to paint on canvases 1m x 1m without any fuss, and in any case you should be able to remix colour if you need too anyway. Don't get bogged down with all this stay wet stuff, and additives, just enjoy painting.

Hi Eltel! I agree with you; I never have problems with Galeria Acrylics drying out before I've used the mix; its simply a matter of housekeeping.

Best wishes,


Steve WilliamPA / RSC Wigan / Warrington / St Helens

If you have to stop painting for a short while spray your acrylics with water, they will then stay nice and moist ready for you to dip your brush into when you return to your work.

Hi Ammar,

This is a common problem, which to be honest I have no solution to other than paint quicker!!! If you need to mix a colour and keep it for more than a week or two I suggest you change palettes. Sorry SAA you didn't hear this! Try an old ceramic plate, mix a small volume of retarder (slow drying gel) into your paint. When you have finished painting, then place some cling film over the plate, sealing it. This will help to perserve your colour for longer. Store away from heat and sunlight. When you return to paint just simply peal off cling film, break skin over the paint surface and your away with the same colour you mixed previously. Once you completed your painting and want to wash your palette, peel off cling film and leave to dry for 24 hours or so. Once paint is dry it can be immersed into hot water and the painting will easily peel away from the palette. I never recommend putting anything like milton solution to a stay wet palette, especially if it comes in contact with the paint at all or possibly the surface you will be working on. It could corrode the palette, paint or surface you are working on and completely ruin your painting long term. Hope I have been of some help.

Hi Ammar,
having had a problem with the 'Stay Wet' palette on the first use,( mould forming), the next time I used it, after giving a good clean I gave the inside a good spray with an antibacterial kitchen worksurface solution, then replaced the two layers of paper and added the paint I needed ---- result ----even after 2 months, a clean palette when I removed the membrane,


The antibac solution didn't affect the colour of the paint at all!