This could be a hippy vintage wallpaper.
Source Tileable Patterns
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin