This really depends on the complexity of your background as well the technology being used.
For example, when using DirectX or OpenGL, all you have to do is utilizing texture wrapping:
- Let's assume your background texture is 64x64 pixels in size.
- To cover an area that is 640 pixels wide, you'd use texture coordinates ranging from 0 to 10 rather than 0 to 1.
- With texture wrapping enabled, this will show your texture repeated 10 times horizontally.
- The same can be done vertically and when adding some zoom factor.
However, if it's about some grid, you might just want to draw the grid on your own using draw calls. Just make sure you only draw to the visible area of the screen (not everything that might be visible in some way). You could also cache these drawing calls to a texture. Using primitives (like lines) rather than textures has the advantage that you can make it more dynamically, like hiding fine grid lines based on zoom level or possibly even animate them (like flashing some important/active gridline).