When I first decided to make actual patterns (instead of just sort-of patterns that don't actually repeat) I tried out Julia Rothman's nice little tutorial on Design Sponge. In the spirit of that, I thought I'd share another way I've worked out, which is to create a .pat file using Photoshop's Define Pattern function. I like this method because it lets me make an image like the one's I'm used to making with traditional materials (i.e. not vector-y) but allows a lot (though not all) of the usability of Illustrator's pattern capabilities. Here goes:
The easiest thing to try first is a simple drop repeat. to do this, I use an image that is vignetted, or sits freely on a page without touching any edges:
Then go to Image/ Canvas Size/and make the canvas twice as wide with the current image sitting on the left side:
It will make it look like this:
Now set some guides. Pull one out for each border and one for the horz and vert center. This will be easy if you go to View/ Snap.
Now open your Layers window and duplicate the layer by dragging it down to the little folded paper icon at the bottom of the layer window. Like this:
This will give you a new layer, but with the image in the exact same spot.
Using the cross tool (or command key), hold shift (to lock horz and vert movement) and drag this image over to the blank (right) side of the composition. Now duplicate it again to create another layer with the image on the right, on top of the last layer. Your layers should look sort of like this:
I've labeled mine for future clarity. Here's why you did this - to create the two halves of an image to make into a drop repeat. Skip ahead for a sec if you need more to see where it's going. For now, it looks like this:
Okay, now we're going to split the right image in half by deleting half of the image in each of the right layers. This is why you have snap and the center guides. So use the marquis box to select the top of one layer, delete it. Now select the bottom of the other layer and delete it. I'll switch my layers to big view so you can see how I've done this:
Now it's over to the cross tool (or command key) to move the halves to the top and bottom of the composition. Again, snap is here to help you on this. Don't forget to hold shift so you don't move from side to side as you do this either. It'll look like this:
This will work as a pattern as-is, but I'd like to add a little textured background first. To keep this demo simple, I'm just going to stick this in without it's own demonstration. A short explanation is it's a mirrored texture that on it's own would look too easily gridded on 90 degree angles, but i think I can use behind the drop repeat without problems:
Now we're going to make it work. Go to Edit/ Show All Menu Items/ Define Pattern. Name the pattern in the pop up.
Now we'll create a pattern layer so we can proof the pattern. Back in the layers window, click on the folded paper icon to create a new layer. Drag the layer to the top and hide your other layers to keep things clear. Now double click on the layer thumbnail where this arrow is pointing:
You'll get this window. Uncheck those two boxes, "blend clipped..." and "transparency..." and check pattern overlay on the left.
Now this is a little secret door. Double click on the words, "Pattern Overlay". It will get you to the options that will look something like this:
Click the blue arrow next to the pattern icon. Mine has some other patterns I'm working on. Yours probably has the default patterns showing. That last pattern is your new pattern. Click it.
Below that is scale. Make this something smaller than 100, so you can see the repeat. You can also move the repeat around in your actual composition by clickng and dragging it. When you get it so you like it, click OK.
Next up you can manage your pattern. If you go to the paint bucket tool in the toolbar, you can manage your patterns easily. Up in the options bar, switch the default foreground option to pattern:
Now go to the small icon next to it and click to see your pattern library. It will include the default patterns, again, mine has some others. Click them individually and go to the Delete Pattern option until only your good pattern is left.
Now go to the Save Pattern option in the same menu. Name the pattern and save it someplace good. You now have a .pat file that you can use on any computer or give to someone else to load. To load a pattern on a new computer, move the .pat to the new computer and go to the same options in the paint bucket and choose Load Pattern.
One other thing, if you print right from a scaled pattern overlay layer, it looks blurry. To get around this, create a new layer under the pattern layer, select the pattern layer and merge it down into the new blank layer (command e). Now it'll look crisper on the screen and print that way too.
So I guess that's a drop repeat. The name of the game is either embracing or obscuring the grid. In this case, the grid is a little hidden because it doesn't repeat on the same axis until two lines over, creating the illusion of diagonals. For something a little more complex, try to set up an irregular pattern that more fully obscures the grid but still repeats. For this, I've made up a few simple tricks to get Photoshop to act like Illustrator's art board, but I don't think I'll get into that right now.