system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] How much web can Spider-Man's web-shooters hold?

How long would it take for him to run out?  
edit: also, do we know what the web is made of?
gpt
His webs are made out of a special chemical that he devised, but we do not know what that mixture is. They are as strong as steel after drying, are able to be fired in quick drying and floppy modes while dissolving away to nothing in 3-8 hours. The shooters likely have settings that inject different amounts of some activating chemcial that tells the webs to harden or soften as needed so he doesn't damage the city's windows as he swings but can also hold down thugs.

How much they hold is unknown but we do know that they can last anywhere from a couple of hours to all night long depending on how much he uses them. So their capacity is typically determined by plot.