Textures That Tile
Photoshop CS3 Tutorial
How to Create Seamless Textures that Tile in Photoshop
If you photograph a texture like a block wall or cement walk and there will be a seam as you display side-by-side copies of your original image.
To make the tiles seamless, it requires a few steps in Photoshop.
Open a texture image in Photoshop (File > Open).
Select the Crop tool and change the settings to 512 pixels by 512 pixels at 72 pixels/inch (ppi).
If necessary, change the units in the Preferences to Pixels.
Click and drag the rectangle to crop the image and press Enter.
From the Filter menu choose Other > Offset.
In the dialog box choose Wrap Around for Undefined Areas and set the Vertical and Horizontal sliders to 256. Click OK.
You may notice some obvious lines in the center. Remove the "wrap" lines with the Clone Stamp tool (s key). Also remove any texture imperfections that would be attention-grabbing.
To test your texture, choose Select > All (Cmd/a (PC-Ctrl/a)) and choose Edit > Define Pattern. Open a new document (File > New) 1024 pixels x 1024 pixels at 72 ppi.
Select Edit > Fill and choose Use: Pattern. Select your pattern from the Custom Pattern swatches.