You can find a variety of styles, including paper-textured backgrounds and minimalist designs, at these locations:
: UHDpaper is a great resource for neon, anime, and landscape art in ultra-high resolution.
High-definition wallpapers with a 1080x1920 vertical resolution are widely available on several reputable platforms that cater specifically to mobile and vertical displays.
: Sites like Pinterest and Wallpapers.com offer extensive libraries specifically curated for the 1080x1920 format.
: For the specific "paper" look you requested, Unsplash and WallpaperCat provide high-quality textures ranging from clean white to dark blue crumpled paper.