You can still install the old wallpapers from submicron. The repository still exists. It is just not in the /etc/pacman.conf anymore for obvious reasons. Everyone has their own set of wallpapers.

You will need to change your /etc/pacman.conf if you want to install them via pacman. 

Procedure

Replace the ArcoLinux lines of your current pacman.conf with these lines.
You can do a copy/paste but delete the older ArcoLinux lines first and then do the copy/paste.
Just to be sure.

Do not delete the Arch Linux lines.

#[arcolinux_repo_testing]#SigLevel = Required DatabaseOptional#Include = /etc/pacman.d/arcolinux-mirrorlist[arcolinux_repo]SigLevel = Required DatabaseOptionalInclude = /etc/pacman.d/arcolinux-mirrorlist[arcolinux_repo_3party]SigLevel = Required DatabaseOptionalInclude = /etc/pacman.d/arcolinux-mirrorlist[arcolinux_repo_xlarge]SigLevel = Required DatabaseOptionalInclude = /etc/pacman.d/arcolinux-mirrorlist[arcolinux_repo_submicron]SigLevel = Required DatabaseOptionalInclude = /etc/pacman.d/arcolinux-mirrorlist

 

With this copy/paste you will get the wallpapers from Submicron back.
We have moved these wallpapers (1GB) to a separate github for easier mirroring and more efficiency.

Type in the terminal

update

Now look for the names via the terminal

type

sudo pacman arcolinux-wallpapers-

and press twice on tab.

Install the screen resolution you like.