We are very excited to announce our new 6 layer PCB service!
6 Layer Prototype Service
$15 per square inch, which includes three copies of your design.
Pricing
For example, a 2 square inch board would cost $30 and you’d get three copies of your board. You can order as many copies as you want, as long as they’re in multiples of three.
Turn Times
Orders will be shipped within 14 calendar days of ordering.
You can get a quote, approve a design, and pay for an order at OSH Park.
OSH Park 
This stackup seems to be significantly worse for RF. Is there any chance that this is still early enough that you could tweak the stack to improve over the 4-layer?
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