Help placing tank backing seam PLEASE

[earhtmother]

So I bought some black foam core sheets to make backing for my tanks(I really do hate seeing cords and the HOB cases at the back of the tank) but I've run into a *small* issue. Sheets are 20x30, tanks are all at least 36 long. I am *pretty sure* I shouldn't put the seam in the middle but NOT sure where I SHOULD place it. Eventually the tanks will be decorated/planted enough that it probably doesn't matter but right now they're pretty empty so the seam will definitely show. Can someone with a bettter *eye* than me tell me what is going to work best for seam placement.

 

[Aiken Drum]

I would say 1/3 - 2/3 would be the most aesthetically pleasing. In reality I would just do a full sheet and a cut for whatever is left.