this post was submitted on 22 Mar 2026
20 points (100.0% liked)

Ask Science

16046 readers
213 users here now

Ask a science question, get a science answer.


Community Rules


Rule 1: Be respectful and inclusive.Treat others with respect, and maintain a positive atmosphere.


Rule 2: No harassment, hate speech, bigotry, or trolling.Avoid any form of harassment, hate speech, bigotry, or offensive behavior.


Rule 3: Engage in constructive discussions.Contribute to meaningful and constructive discussions that enhance scientific understanding.


Rule 4: No AI-generated answers.Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.


Rule 5: Follow guidelines and moderators' instructions.Adhere to community guidelines and comply with instructions given by moderators.


Rule 6: Use appropriate language and tone.Communicate using suitable language and maintain a professional and respectful tone.


Rule 7: Report violations.Report any violations of the community rules to the moderators for appropriate action.


Rule 8: Foster a continuous learning environment.Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.


Rule 9: Source required for answers.Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.


By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.

We retain the discretion to modify the rules as we deem necessary.


founded 2 years ago
MODERATORS
 

Maybe it’s just been the “apple barrel” cheap brand, but it seems that the lighter green varieties turn into a completely thin green liquid after a few years that smells vaguely like an alcohol/“chemical-ly.”

It’s specifically the greens that do this, so I’m wondering if there’s something in the green pigment that reacts with the binder after time. Most other cheap acrylics tend to dry out - reds more so. Is there some sort of slow chemical reaction happening with the greens instead?

Edit: I found a bottle of Orange just now that went off in the same way. Apple Barrel, matte, “Pumpkin Orange” 2047E.

It’s just a very striking way for paint to degrade. Drying out or just have the binder separate I get, but this one has to be involving some sort of fun chemistry.

you are viewing a single comment's thread
view the rest of the comments
[–] irotsoma@piefed.blahaj.zone 6 points 1 week ago* (last edited 1 week ago)

I can't say without knowing the specific ingredients and solvents, but just in general.

Different ingredients used for coloring dissolve differently in various solvents. Unfortunately, colors that are not from single ingredients sometimes have to be made from ingredients that don't dissolve well in the same solvents. Also, different solvents and ingredients are less shelf stable than others or react more with oxygen or light.

Generally, if you want to keep pigments, or anything really, from decomposing, you need to store them in the dark or a totally opaque container and in a vacuum or in a very well sealed container, preferably topped off with an inert gas, or at least not oxygen which is very volatile.

The alcohol or chemical smells usually are the solvent evaporating. Things that harden in without special additives or things like UV do so by the solvents evaporating. The quicker the solvent evaporates, the quicker the paint sets. Alcohol evaporates much faster than water, for example.

Anyway, the containers that cheaper paints come in, generally are not 100% air tight or light blocking. (Remember, many thin plastics are air permeable, just barely, air particles are way smaller than water particles so something can be water right but not air tight.) Often I put my paints and similar things I dont use often in a vacuum bag that you cam pump the air out of and store them in a thick, dark box.