BenJackson:
I’m interested in 4 layers, but batchpcb is only cost effective for tiny boards. 18 square inches of 4-layer PCB here costs as much as 180 square inches at other no-touch vendors. If I ordered my boards from batchpcb they’d cost $1450! Even 2 layer they’d be 3x as much as a 4 layer board made elsewhere.
batchpcb is a great option for small boards, but I’m not sure what you guys were expecting with these prices…
180 square inches, electrical testing, unlimited vias/holes, 1oz copper, silkscreen on both sides, all for $144?
Please post or PM this companies site, thank you.
After all the original people asking us for 4 layer designs, we’ve seen exactly one design run.
One reason for this may be because the BatchPCB FAQ still says that only 2-layer boards with 20-mil holes are supported. If you modify it to point out that 4-layer boards with 15-mil drills are possible for 2x the price, it may generate some more interest.
I’d be interested in helping increase the level of interest in 4-layer boards, myself, since I’ve been awaiting panelization since August 23. I assume that’s because it takes a long time to accumulate enough 4-layer orders to make a batch.
If it helps, I’ll be glad to share my EAGLE .DRU and .CAM files for 4-layer jobs, once I get a board back and verify that they work. 
John Miles KE5FX:
After all the original people asking us for 4 layer designs, we’ve seen exactly one design run.
One reason for this may be because the BatchPCB FAQ still says that only 2-layer boards with 20-mil holes are supported. If you modify it to point out that 4-layer boards with 15-mil drills are possible for 2x the price, it may generate some more interest.
I know I’m weak-minded, but I read here that you could do 4 layer boards, went to batchpcb.com, saw it said you could only do 2 layer boards, and then came back here not fully convinced that you could do 4 layer boards. I assume if you just process a 4 layer job that it will go through? Not sure my next design will require 4 layers, but this is a nice service.
I’ve done two 4-layer boards now through BatchPCB, and they work fine. The last one is an 8-GHz synthesizer, in fact.
If you submit a 4-layer job within the supported feature constraints, it’ll work. Downside is that it will take longer to get your board, since nobody else knows they can do this at all. Plan on 3-4 weeks from order to delivery, in my (limited) experience.
For those interested in examples of 4-layer PCB design under EAGLE using rules compatible with BatchPCB, you can download all of my PCB files from my first two projects, from design rules to final Gerbers, here:
http://www.ke5fx.com/cg.htm (VHF/UHF comb generator)
http://www.ke5fx.com/hpll.htm (8 GHz PLL)
Being my first boards, these are not intended to serve as examples of great RF PCB layout skill. The only things they have going for them is that they were accepted by the BatchPCB bot, and the boards worked well.
Hope they help make the 4-layer service more popular, so I don’t have to wait a month for the next one.