A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The tile can be had by using shift+alt+i on the selected rectangle in Inkscape
Source Firkin
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
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
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin