Ever had this problem?
You make a sideborder background and the shadowing breaks at the seam lines?

A ShadowStick will take care of that problem.

So what's a ShadowStick?  It's a transparent shadow that you can copy/paste and flush to the edge of the side border rather than using the drop shadow.  You can save it as a PSP file to use over and over and over and make a set of different depths of shadow.

And here we go!
 

Step 1
Click on you rectangle selection tool and check the Tool Options panel, match the settings below.

Step 2
Open a new image about 600x600 so you have plenty of working space and make a rectangle selection with the length you want the shadow to run.  Make sure the selection is much wider or longer than where you intend to use it.

Step 3
Next we will apply the drop shadow.

Step 4
Don't pay any attentions to the opacity or blur - those are purely a matter of your preference.  Choose your settings and then click OK.

Step 5
You now have something like this.  Starting outside the shadowed area, make a very long selection starting from the outside of the widest shadowed area and moving into the rectangle past the cutoff of the shadowing.

Step 6
Since I made the horizontal stick, I will now turn the stick.

Step 7
Rotate by 90 degrees either direction - doesn't matter.

Step 8
Now Copy 

Step 9
Now Paste to a new image

Step 10
You now have a ShadowStick with whatever shadow depth you chose for the blur.

Step 11
How to use it?!  Make a sideborder image and paste the shadow to it.  You may have to mirror it, as you want the darkest edge toward the sideborder.

Step 12
Move the shadow flush against the sideborder edge.

Step 13
It's done!  Your sideborder has a perfect shadow that will tile perfectly.

Step 14
Save yourself heartache, always DESKCHECK it before using it on a page or stationery.  I need to make a 'Deskchecking' tutorial, even though I've covered it in several other tutorials.
  

Here's a sample using the ShadowStick at different levels.

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tutorial by CSGreen
 

Zipped tutorial in PDF format . . . 697KB

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