A tutorial for beginners on how to create a seamless pattern in Adobe Illustrator using the blob brush, smart guides and clipping path tools.  The version I’m using is Illustrator CS4.

1. Go to File > New and create a new image 400px x 400px (you can increase the image size but keep it to even numbers)
2. Turn on Smart Guides (this will help you to line up your elements) go to View > Smart Guides.
3. Draw a square to cover artboard (400px x 400px) make sure its in the center)
4. Create a new layer and lock the first layer. Select the blob brush, double click it to bring up the options box and change the size to Random (you can use any size) – see image below:

5. Change the blob brush to a colour slightly darker than your background colour. With the blob brush selected, click on the left side and top of your image, so you get random sized circles – like the image below:

6. Now to line them up. Select all the vertical circles on the left side and click Horizontal Align Center:

7. Move them toward the left edge of the artboard until they ‘snap‘ into place (thanks to the Smart Guides) see image below:

8. Do the same with the circles at the top (Vertical Align Center). Select all the circles on the left, copy and drag to the right side until they ‘snap’ (press ALT + SHIFT) while dragging the circles – see image below:

9. Do the same with the top circles – you should end up with something like this:

10. Now we need to add circles to the center, select the blob brush again and click inside until you get the effect you want. Here’s mine:

11. Select all your circles and group them. Unlock Layer one , select the background, copy and paste it on top of your circles (CTRL +C , CTRL + F). Select your circles and the copied background, right click and select Make Clipping Mask:

12. Your image should now look like this:

13. At this point we should test the image to make sure that it is seamless so far. The easiest way to do this is to make it a Desktop Wallpaper. Go to File > Save for Web and Devices, and save it as a jpeg in your My Pictures folder. Now go and change your desktop wallpaper, choose the image you just saved and tile it. It should be seamless, here’s a screen-shot of my desktop:

(If there are any problems – check the circles on the edges of your image in illustrator to make sure they are lined up correctly)
14. Create another layer and lock layer 1 and 2. Choose an image that you want for your main pattern. I’ve chosen a VW van, and we need to repeat the steps we’ve already done for the circle pattern.  So, copy and paste ( press ALT + SHIFT while dragging) and align your elements to the left and top until they ‘snap’, and again Align your elements Horizontally and Vertically and copy the left and top elements to the bottom and right. Here’s mine:

15. Now add some more elements to the center (play around with them a bit to get them as random as possible) like so:

16. Select all your elements on this layer and group them. Unlock layer 1 and copy (CTRL +C) and paste (CTRL +F) on top of your elements. Select both, right-click and choose Clipping Mask. You should be left with something like this:

17. Now, test it again as a desktop wallpaper to make sure it’s seamless, and your done! Here’s mine:

Hope this tutorial was of use to you, and if you enjoyed it – please share it!

Tracie x