Looks like an old rug or a computer chip.
Source Patutin Sergey
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Colourful background achieved with gradient fills.
Source Firkin
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
A yellow tiled background... Blurriness, bokeh effect and rectangles pattern in one mix.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Prismatic Abstract Background Design
Source GDJ
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin