More Textures
Seamless 3D Isometric Tessellation Pattern 2 #147
 Light  CC 0

A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).

Source GDJ

Old Mathematics #43
 Stripes  CC BY-SA 3.0

This one takes you back to math class. Classic mathematic board underlay.

Source Josh Green

Prismatic Abstract Background Design #403
 Noise  CC 0

Prismatic Abstract Background Design

Source GDJ

Background Patterns - Citrone #248
 Fabric  CC BY-SA 3.0

If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117

Source Viscious-Speed

Background pattern 339 (colour) #1708
 Yellow  CC 0

The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Background pattern yellow #1999
 Yellow  CC 0

Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Graphy@2X #351
 Grid  CC BY-SA 3.0

Looks like a technical drawing board: small squares forming a nice grid.

Source We Are Pixel8

Tessellation 15 (colour 2) #2221
 Yellow  CC 0

The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin

Dark Stripes@2X #40
 Dark  CC BY-SA 3.0

Very dark pattern with some noise and 45-degree lines.

Source Stefan Aleksić

Batthern #324
 Grid  CC BY-SA 3.0

Sometimes simple really is what you need, and this could fit you well.

Source Factorio.us Collective