Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Prismatic Groovy Concentric Background No Black
Source GDJ
The tile can be had by using shift+alt+i on the selected rectangle in Inkscape
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Prismatic Abstract Background Design
Source GDJ
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A new one called white wall, not by me this time.
Source Yuji Honzawa
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin