Basically they mean the same thing.

KenjiAlpha said:
Basically they mean the same thing.

Okay... I think you mean alias. Otherwise you'll have two tags that mean the same thing and only cause clutter.

Plain_background is mainly used for single-color backgrounds (bucket fills), whereas simple_background is used for simple patterns such as gradients.

But those tags are currently bit messy. For example, tagging an image with any color tag (white_background, rainbow_background etc.) implicates it with plain_background: #307009 #297298 #322135 #302736

It'd take massive amount of work to sort them out, so is it worthwhile to keep simple patterns separate from plain backgrounds? Maybe they should be aliased. On the other hand, if someone searches for plain_background, I doubt they're looking for images such as #2503 ...

Genjar said:
simple_background is used for simple patterns such as gradients.

We have gradient_background for that...

Ayup. But that is generally how it seems to be used: as a catch-all for backgrounds such as gradient_background, pattern_background and abstract_background. And the ones that are hard to fit under the other background tags: #266321 #317423 #315222

As I said, it is a bit messy.

TheHuskyK9 said:
We have gradient_background for that...

Gradiant_Background should imply Simple_Background IMO

I've only ever used plain_background for a single-color fill. Never used simple_background, because I don't often find backgrounds that qualify for it that also don't qualify for a better tag.