The jig comes when you order a sample kit. transfersupplies.com I think it is and ACP distribute for Paul of Octi Tech that is the manuf of them.
They are expensive. Over at dyesub.org you can read more up on them. Discussion to about the metal interferring with the reception and all also.

Won't let me cut and paste the actual link.
Search IPHONE and pick 6 months. 
Its under the commercial discussion.

One post
Apple already has had signal reception issues with the iPhone 4. Adding metal is not a good thing.

http://news.consumerreports.org/electronics/2010/07/apple-iphone-4-antenna-issue-iphone4-problems-dropped-calls-lab-test-confirmed-problem-issues-signal-strength-att-network-gsm.html

several more links about it.
FYI

http://www.computerworld.com/s/article/9178503/Hardware_expert_explains_iPhone_4_antenna_problem

http://www.wired.com/gadgetlab/2010/10/sleek-metal-cover-replaces-glass-iphone-4-backplate/

http://www.anandtech.com/show/3794/the-iphone-4-review/2

http://www.pcworld.com/article/199853/apple_responds_to_iphone_4_antenna_problem.html

http://forums.macrumors.com/showthread.php?t=1085984

http://www.pcworld.com/article/199848/iphone_4s_antenna_boosts_voice_and_data_rates_with_one_big_flaw.html

http://meta.ifixit.com/Answers/View/1823/iPhone+4+transparent+rear+glass+replacement+missing+antenna

http://marianneschultz.com/2011/07/27/review-mas-elements-replacement-titanium-back-for-the-iphone-4/

http://reviews.cnet.com/8301-19512_7-57338687-233/elements-swanky-vapor-epiphany-iphone-4-4s-case-ships/

ready to place an order with Conde and would like to know what paper are you using, and if it can be used for mugs too

If you don't mind sharing a link I'd appreciate it 

Thanks a lot!

I use the dye trans also for 99% of my stuff

To be fair, virtually none of the links that you posted mention anything about a metal back cover having anything to do with reception whatsoever.  In fact, one mentions getting the same reception after replacing the OEM glass back cover with a titanium cover.  The outer band of the phone is the antenna, which caused all the controversy when they first came out, with people ham-fisting them, so to speak.

I couldn't search 6 months on dyesub.org, but a search for "iphone" came up with no results.

In any case, I have people testing them, but based on the idea of diminished reception solely based on the fact that there is metal in cover, I don't buy it.  It reeks of propaganda from the more expensive covers, both the shrink-wrap style and the transfersupplies kit.

Well the articles are from way before the cases came out, so doubt its any conpiracy to sell covers and didn't say that the covers would or wouldn't cuz issue. It was brought up on the forum . And could effect some people. If I recall right not all phones had issues. Some did.

Not sure what your doing wrong on the search but IPHONE brings up the discussion of it and on the Octi Tech covers. Some 90+ posts.   

I know some Iphone users tho not many and seems some have issues with reception in certain places while another won't. 
In my day job we work in a all metal building and buddy has no issues but at his trailer no reception. And I think he said his trailer is closer to the tower. Go figure.  I just like to be aware of these things. Gives me more info to troubleshoot. Guess its from my computer/ISP days.