If you already have a design for your site that you’d like to follow with pixel-precision, there is no need to grab a ruler! You can use the design as a tracing image, showing up semi-transparently in the editing area, and all you have to do is to place the Page Parts in the proper position on top of the tracing image. Page Parts are semi-transparent while you are moving them, so that you can see the tracing image below. You can also temporarily bring the tracing image to the top and back to the bottom, so you can immediately see if there are any positioning problems!