A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A seamless stone-like background for blogs or any other type of websites.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green