Now you’ll need to position your graphic elements on the tile. Toggle on the layer visibility for the first element you created and then choose Filter -> Other -> Offset. (If you’ve created any vector objects, you’ll be warned that the vector mask will be rasterized before continuing.) Once the Offset window appears, check the preview option (if it’s not already checked). Immediately below, you’ll see a set of options for Undefined Areas; click the Wrap Around radio button.
Now move the horizontal and vertical sliders to position your graphic element; as you’ll notice, you can push the graphic off any edge of the document and it’ll simply wrap around to the other side. Position the graphic element and then click OK. Simply repeat this procedure for each element, and you’ll construct an interesting pattern in no time.
Offset lets you move images and have them wrap around to the other side of the canvas.
Follow these steps to export your pattern:
* Choose File -> Save for Web & Devices.
* Choose PNG-24 from the Preset pop-up menu.
* Make sure that Transparency is not checked.
* Make sure that Convert to sRGB is checked.
* Make that the projected file size (seen in the bottom right) is less than 800k.
* Click Save and save the file to your Desktop.
You can export as GIF, JPEG or PNG, but PNG will give you the best quality output.
Putting your pattern on Twitter
Uploading your pattern is straightforward. Go to your Twitter home page and click Settings; once the page loads, click Design. Immediately below the default themes, you’ll see an option Change background image. Click this link and then click Choose File. Find the pattern you saved to your Desktop and then click Choose. Check the option to tile background and then click Save Changes. Your new look is locked in -- now tweak the design colours (text, links, sidebar, etc) to match,