A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
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
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
From a drawing in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
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
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen