Lovely pattern with splattered vintage speckles.
Source David Pomfret
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A white version of the very popular linen pattern.
Source Ant Ekşiler
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
The base gradient edited so now more details are rendered.
Source Lazur URH
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
One more sharp little tile for you. Subtle circles this time.
Source Blunia
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen