Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
Prismatic Triangular Background Design Mark II 5
Source GDJ
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Prismatic Snowflakes Pattern No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso