if you must use invisible thread, try YLI. but, for the life of you, try not to have to. DO NOT USE THE CHEAPER BRANDS NO MATTER WHAT :evil:
i use bottom line on the bottom and king tut on the top, as well as valdani on the top. i wait for sales at bayside quilting. if you get on their mailing list they inform you of their sales.
http://www.baysidequilting.com