I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Prismatic Abstract Geometric Background 4
Source GDJ
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
The image is a design of blue glass.How about using it as background image?
Source Yamachem
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ