[TazeTSchnitzel]

Are images even necessary, anyway?

Unicode has playing card codepoints (the full 52) and playing card house codepoints (️, ️, ️, ️).

Edit: What the hell? Hacker News stripped the Unicode characters?! https://news.ycombinator.com/item?id=10156894

[CharlieHess]

You can't control the font rendering in Slack (it's Lato, at a certain size). The Unicode cards are far too small to read.

[TazeTSchnitzel]

I did think of that. But you could use the symbols for the houses and pair them with a number/letter.