Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Old China with a modern twist, take two.
Source Adam Charlts
A free pink background pattern.
Source V. Hartikainen
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
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
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed