I'm building a grid-based game for iPad, and for usability purposes I've selected my game grid to be built of 75x75 squares. However, so far I've seen that the majority of (free)texture catalogs I can find are either 16x16 or 32x32. 

Currently I have the graphics engine stretch the 32x32 texture onto a 75x75 tile, which does not look very sharp.

How can I make my game look good -  **do I need to create textures whose size is equal to my game tile?** Should I try to stitch multiple textures together (like 4 texture squares per game square)?