What is the minimum space betw

What is the minimum space between a pair of tracks on a PCB that could be manufactured?

Problem
What is the minimum space between a pair of tracks on a PCB that could be manufactured? 

Solution
Through this service, we can guarantee (6)six mil spaces and six mil trace widths. The software will let you know if you have created any violations. You may choose to ignore these warnings and go as low as (5)5 Mil spacing; however we have placed these limitations because these are the manufacturing parameters that we can produce reliably. If you choose to create a design with Trace and Space width smaller then (6) Mils you do it at your own risk and PCB123 accepts no liability if your board fails.