A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
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
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A textured orange background pattern with vertical stripes.
Source V. Hartikainen
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin