I really need help.  I have a wedding cake that I need to make that is 4 cakes/tiers high.  On the bottom cake and on the 3rd level cake I need to make barbed wire swags.  I have never done this before.  I think i need to make them early so they can set up and be spray painted silver.  But I don't know how to get all the swags the size they need to be.  I already made some, by putting them over an oatmeal box and they turned out way to tall for the layer they need to go on.  I don't to keep guessing on the item i place them over to dry whether or not they will be the correct size or not.  I really don't know how to do it. Please any advice would be very helpful.  I don't really want to make them the same day I bake/decorate the cake because of time restraints.  I would like to do as much as possible before hand. The 2 cakes the swags will be on will be on a 12 inch round cake and an 8 inch round cake, and yes, they will be stacked, so 2-12 inch cakes stacked and 2-8 inch cakes stacked.    

First off what are you making the swags out of?

Second when you say "spray paint" you mean "edible spray glitter" right????

Third I would use the cake pan that is the correlating size of tier and place them to dry around that. For visual reference and circumference.
 

Ok I saw the picture of the cake in another thread. I would just make the bows in advance the swags I would do day of. You could just use a pasta machine or polymer clay press and make the long strands. Twist and and swag then unswag and measure. Then just cut each set of rope exact same length and twist. Does that make sense. You said it was an 8" and 12" so just divide by the width of each swag. So if you wanted distance between each swag to be 3" for the 12" then you'd have 4 swags. I think one of the problems I'm seeing is the cake pictured seems much larger than these sizes. So the swag will not be as dramatic because the distance allowed around the cake. If that makes any sense?
 

I will be making the barbed wire swags out of fondant/tylose mix.  I have an airbrush and will be spraying them with edible silver luster spray paint.  As far as the cake pan, good idea, however, is there a standard size of swags??  For example 6 inch, or so, that way they don't get to big like what has already happened to me with the first ones I made??  I want them to be sort of big, like hanging down around 3/4 of the cake.  

Sorry had my math wrong its late havent had dinner.

K so the 12" cake is a 36" diameter. So divide 36 by say 6 and you'd have one every 6 inches. So you just need to mark 6inches on a piece of paper. Then make the swag the dip depth you want. Then straighten it out and measure that. That is your standard size for all the swags. It will measure longer than the 6 inches but once draped in the 6inch area will be perfect. You could even mark the bottom of the dip on the sheet of wax paper so they all lined up perfectly. They should be plenty deep. Does that make sense? Then just do the same thing with the 8"

Thank you so much for your help.  I really do appreciate it!!     

Yep no problem, sometimes my brain functions every once in a while. Its so demanding with its food requirements.
 

Smittyditty, can you post the picture of the cake?

http://cakecentral.com/t/761408/looking-for-this-item-for-a-cake-can-you-help#post_7420268

She had posted another thread asking about the buckles that is how I saw it.