Do you use either a retarder or Open when painting?
I use Golden OPEN acrylics when painting plein airs because they tolerate cold temperatures. I’ve painted down to 7° + wind and they worked great. Regular acrylics stop working for me around 50°. Something goofy happens with the binder and they get stringy and gummy. Neither type of acrylics work well in wind so oils are my go-to medium if it’s windy. No retarder. That stuff is terrible plus it just adds nuisance work to the prep having to mix things into paint prior to working. At home, I only use regular acrylics though, nothing added, no fancy sprays or anything.

I like to mix back into mixtures on the palette, but with acrylic they dry quickly (especially outside) leaving a film that doesn’t reconstitute to paint but trash.
The OPENs stay wet on my palette for a long time (days, maybe even a week inside my french easel, if I put them in a covered box they’d probably last indefinitely). Thin mixtures on the palette will dry quicker if there is a breeze or if there is sun on my palette, but usually everything is still wet after I get home. Sometimes lately I’ll add molding paste for some body because OPENs are kinda thin. This accelerates the drying drastically.

You may like this acrylic paint by Chroma. It’s called Interactives. They sent me some free samples. You can re-activate dried paint with some special medium so those dried piles on your palette can still be used. It was a little complicated for me but seemed like an interesting idea.

Does keeping the palette wet with spray bottle work for you?
Absolutely no water with OPENs when I’m outside. I even clean my brushes when I get home. For regular acrylics a spray bottle is a necessity to keep the palette moist. Other than that I don’t use much water.

And with regular acrylics I don’t consider keeping mixtures wet like oil painters do. I mix what I need for the note I’m about to apply and then I move on to the next mixture I need for the next note. If I need to revisit a passage I remix the color. I’m not trying to paint something really tight and flawless so any variation in the mixture is not only welcomed but I deliberately try to vary it. The layering ability of acrylics gives a wonderful pentimento effect that I love. My palette is thickly covered in small colorful circles of old mixtures dried one on top of another. I mix, apply, move on. If for whatever reason I need to match a color it isn’t very difficult to do since I can usually remember what I would’ve mixed for the original color.

I also like preserving left over oil paint in the freezer to prevent waste. How do you deal with acrylic paint waste? Stay wet palette?
For OPENs I just have them on a piece of plexi, that’s it. You can see it in a lot of my photos. It stays open long enough that I don’t waste much between painting sessions. I do use covered palettes for regular acrylics though. I don’t use the stay-wet sponge things or anything like that. Just a piece of plexi inside the box to mix on. I’ll spray it with water before I close it. The amount of paint I lose is pretty minimal. I don’t expect it to stay wet for weeks so I squeeze out what I expect to use. As they say, you can’t make an omelet without breaking some eggs so I don’t worry about that too much. For soft body acrylics in the summer I sometimes use a 7-day pill holder. That works better than my original ice cube tray contraption. Zip-lock bags work great too if you have a small palette with wells.

Marcia Burtt has a lot of info on her web page. She uses a fishing tackle box with a gasket around the lid. I keep wanting to try that but I only use 7 colors so it seems like it may be too big for me.

Hope this helps.

oils, 12×9″

acrylic, 12×9″

acrylic, 12×9″ 

I tried to give this the feeling of wasting away and dissolving.

acrylic, 12×9″ 

Yesterday’s landscape was a disaster. I usually show my failures but this time I think I’ll wait until I fix it so I have a little more to talk about.

BEFORE (04-14-2012)

AFTER

It’s acrylic, 16×20″, with a somewhat limited palette. I didn’t plan on repainting the entire thing but I ended up doing just that. The drawing had been bothering me and I planned on just fixing that (the distant section. You can see it’s smaller now and pushes the space back more.). Now the painting looks completely different.

I got out there not long after sunrise and spent my entire morning there. It’s such a nice spot it’s easy to lose yourself. I wanted to fix another old one but didn’t have time. Maybe tomorrow. This one has a couple of little problems that I’ll fix in the studio.

acrylic, 12×9″

acrylic, 8×10″

Then I drove to a parking lot where I could stand under the hatch on the van. This one I tried to let the painting lead the way.

acrylic, 11×14″

Sunday’s sunrise attempt. Always a challenge, and since it’s impossible to catch the sun as it’s rising it’s also always a good opportunity for me to let go of reality a bit more. The unforgiving and always moving (not to mention blinding!) sun helps me remember to let go because it is hopeless to try and be “true” to the event. I doubt I’ve ever seen a sunrise/sunset painting that “looks just like a photograph!” that wasn’t actually painted from a photograph.

acrylic, 8×10″ 

Then I had time for two more. I just love the sun coming up before 6 am in the summer months! I didn’t even have to rush and it’s only the beginning of May.

acrylic, 11×14″

acrylic, 8×10″

Getting closer to my drawings with this one.

acrylic, 11×14″ 

Didn’t capture the light very well but this was fun anyway. I was hoping with such limited time it would break down more into abstract shapes.