A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Green Background Pattern
Source V. Hartikainen
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
Prismatic Polka Dots Mark II No Background
Source GDJ
White handmade paper pattern with small bumps.
Source Marquis
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo