Is there a way to prevent the oil paint on my palette from drying?

I know that oil paint will stay wet at least a week, but what if I'm working on a big painting and I want the colors that I mixed on my palette to be wet for at least two weeks?Is there a way to prevent the oil paint on my palette from drying?
I used to put a few drops of linseed oil on mine and cover my palette with cellophane when I wasn't working with the paints.Is there a way to prevent the oil paint on my palette from drying?
Put medium on it and it comes back.
What I do quite simply is mix a little retarding medium in and then put plastic wrap (saran wrap/glad wrap......different countries call it different names) over the areas i don't want to dry up. Even in dry hot temps this will prevent your paint from drying.


Alternatively if I'm working with larger amounts of color I mix the colors in glass jars that have lids. Then I use what amount I need at he time on my palette keeping the remainder of the mix in the sealed jars ready for when I need that mix again.


Hope this helps.
If you use the disposable paper oil painting tablets 9x12, you can get these nifty plastic cake containers at the grocery store with covers for about a buck. they fit perfectly over the palate paper and will seal your paint for the night. (Mist with a bit of turpentine if it is going to be awhile before you use them.


The other suggestion is to not put so much paint out at one time. Mix what you are using. In fact try this trick. Use two paper pallets,one for warm colors and one for cool.


I know some artist who store their mixed paint in baby food jars for fear of not being able to get the color again. You could do that too, but I think it is far easier to learn to mix smaller amounts and get the same color every time.