This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Prismatic Triangular Background Design Mark II 5
Source GDJ
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
"Beige Stone", Tileable Texture.
Source V. Hartikainen
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts