Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless texture of a rough concrete surface.
Source V. Hartikainen
The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.
Source Yamachem
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Prismatic Abstract Background Design No Black
Source GDJ
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen