Creating a wavy, engraving-line background

In this move, I'll show you how to create this pattern…of wavy yellow engraving lines, at the back of the certificate.…And, as it just so happens, it's a single horizontal…line, with just two strokes assigned to it and that's it.…So, let's see how it works, I'll go…ahead and switch over to my document in progress.…And I'm going to select this top…horizontal line using the black arrow tool.…And then I'll go ahead and drag it upward like so, to about…this location, kind of splitting the difference between it's…previous location and the top of the yellow rectangle.…

And then in mid-drag, I'll press and hold the Shift and…Alt key, that'd be the Shift and Option keys on the Mac.…Keep those keys down, and then release the line in order to create a copy of it.…Then I decided I needed to scale the lines,…so it's as least as wide as the certificate.…So, I'll doubleclick on the scale tool icon, here in the toolbox.…Now,…I went with some non uniform values here.…I change horizontal to 130%, and left vertical set to 100%.…