A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A comeback for you: the popular Escheresque, now in black.
Source Patten
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Prismatic Abstract Background Design No Black
Source GDJ
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is the remix of "plant pattern 02".I changed the object color to white and the BG to purple.The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin