How big would you have to do that in a drawing program and how do you upload that to Minecraft? And if it's not about Minecraft itself, how then, because I've seen myself that others can do it.
Did the other players have a mod installed? (Java Edition)
I can't remember that the Java version of Minecraft also lets you upload / use HD skins.
Which version are you playing on?
I'm currently playing the latest version, I think 1.16.4
You can't upload skins in Minecraft itself. You have to do this via the Minecraft page (http://www.minecraft.net).
When I'm at home, I'll see if that's really possible on the Java version. But if I remember correctly, that only worked on the Pocket / Bedrock Edition of Minecraft.
Otherwise I can recommend a Minecraft client called "LabyMod". There are many add-ons there that you can easily install and there would also be the HD skin function.
If you have installed the addon correctly, you can insert an HD skin and use it.
If you play Minecraft on well-known servers like "Gommehd.net", you will find many other players who also play with LabyMod. You may also see other players walking around with an HD skin too.
If you are interested in this mod (LabyMod) and need help, please feel free to contact me or the Internet.
To install LabyMod, you must first download and install Java: https://www.java.com/...manual.jsp
Then you can download and install the mod on the official LabyMod website: https://www.labymod.net/de/
But then I would have to show you where you can install the HD skin add-on. If you'd be interested, I'll be happy to do this when I'm at home.
