G-String, (and they promises that the name comes from the top string on a Ukulele and has nothing to do with strippers), are an Oahu firm founded in 1993 by Derek Shimizu who, in the beginning was the only luthier. As time has gone on the business grew to be a very well respected and influential major Ukulele manufacturer in Hawaii. It ran more along factory lines with each employee responsible for a specific part of the finished Ukulele rather than being a collection of luthiers who all make individual instrument under the banner of G-String. The reason for this is the production line method produces more consistent quality, however all staff there can produce a Ukulele from start to finish on their own, and if they can't when they start they are taught how to. This in house training is one of the reasons for their influence, a lot of the independent luthiers in Hawaii, like Gareth Yahiku and Mark Bajet, started out learning the trade as employees of G-String. It also leads to all of the employees making their own, (kind of journeyman piece), Ukulele which they can keep sell or whatever. 

Another reason for their influence is they amongst the first to embrace modern technology in the manufacturing process, using CNC cutters and Lasers, to produce top of the range Hawaiian Ukuleles. This modernism also shows in some of their design with laser etching and alternate soundhole and headstock shapes. The Ukuleles themselves came in all scales from Soprano to Baritone and all string combinations up to Taropatch, (I've not seen a G-String Tiple Ukulele). They were predominantly made with koa but I have seen a few spruce and cedar tops. 

In 2009, Shimizu closed the workshop down, moved from Halawa Valley to Hilo and went back to being a one man operation. In 2014 he left Hawaii and moved to Las Vegas where he is still in business as G-String making mainly Concerts and Tenors. He still has his laser and he does make other scales as custom options.