Wet pallete question

Some paints don't re-hydrate well (any of my whites are done after the first day). Make sure you've got the sponge/paper towel fully saturated. Sometimes you need to add more water to it throughout the painting session (with the dry winter air right now, I have to add more about every time I refill my drinking water). Also, some papers aren't all that great and won't get the moisture up to your paint. I have a P3 painting pallet and ended up trashing half the papers it came with as baking paper is much better.

 

On my experience with a wet pallete (I had to start using one after moving to Madrid... that 50% or so less humidity really shows up XD) is:

• Grab a cheap piece of tupperware
• Grab a cheap wipe, cut it to the size of the base of the tupperware. I use two layers of the cheapest (it's like 1 euro per roll).
• Grab some vegetal paper (it's used for oven cooking, kinda like rough semitransparent paper you put under what you wanna cook so it won't stick to the mold) and cut it to the same size of the wipe.
• Pour water on the wipe, so it is throroughly wet.
• Place the vegetal paper
• Place the lid when you finish!

The type of paint is quite important however. None of the metallics I use react well with a wet pallete, and the rest of the colors are Vallejo. Try to get the good amount of liquid, since too much will decant the pigments and leave stained water, and too little will leave a dessicated smudge. Also, mix before using the stored color.

 

All of the above and specially emphasis on the metal paint, I d'ont know how some people can use them with water. I have a lot of problem myself so in the end I use medium for those kind of paint.
My own wet palette is made of piece of foam from an infinity box, random baking paper (still I ensure that it is a white one not a yellow one to avoid false color render) in a plastic box. If I keep it in the fridge between session it will last even longer.