You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
Prismatic Floral Background No Black
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein