Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
CC0 and seamless wellington boot pattern.
Source SliverKnight
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock