What you're seeing there is primer, not a plastic cover. As you know, primer is used to get paint to bond to aluminum, which is what we used for the G5's body. The aluminum alloy we sourced is known as LM201b (patent pending) and was developed at the Korea Institute of Industrial Technology for use in automobiles and aircraft. LM201b, unlike the aluminum used in other smartphones, is diecast unibody which makes it very sturdy while still maintaining lightweight properties. We figured out a way to integrate the antenna bands into the aluminum seamlessly so you can't feel the lines and covered the LM201b with primer and paint using a process called microdizing which means that tiny particles of metal are infused in the coating and bonded to the aluminum. I think it's incorrect to say that a product isn't all metal if paint is involved. That's like saying cars and airplanes aren't metal because they're also painted. For the record, even metal that's anodized will scratch off. Our process may be different but it achieved what we were aiming for, which is a smooth, seamless metal finish that's durable and lightweight. We weren't interested in doing what has already been done. When did this become a bad thing?
翻譯過來，
就是 G5 機身上類似塑料的其實是底漆（primer），因為它對於金屬具有極強的吸附能力，這也是為何用在 G5 身上的原因。
而 G5 使用的金屬鋁為正在申請專利的 LM201b，是由韓國工業研究所研發用於汽車和飛機的製造，壓鑄一體成型后的機身非常堅固而且輕盈。
LG 找到方法將天線無縫融合在鋁製機身上
如果說 G5 這樣不能算作金屬機身的話，那麼經過塗裝的汽車與飛機也不能說是金屬機身了。我們在 G5 身上實現了平滑無縫的金屬機身，並且保證了堅固耐用和輕量化，這難道是是件壞事嗎？
各位機油可以放心購買 G5 了，這機身可是用了在汽車和飛機上工藝，而不是一般的噴砂處理哦。（笑）
----------------------------------------------------------------------------------------
http://www.newmobilelife.com/2016/04/04/lg-g5-build-controversy-clarifie/
日前 LG G5 被用戶指銷售手法有誤導成份，LG 在銷售 LG G5 時表示使用全金屬機身，但有購買了 LG G5 的用戶發現並非如此，LG G5 除了金屬還有塑膠和鋁合金！因此 LG 官方不得不親自回應相關事件，LG 全球傳訊總監 Ken Hong 表示用戶所發現的「塑膠」其實只不過是一層油漆，而並非是塑膠，堅稱 LG G5 是使用全金屬製造！Ken Hong 同時表示：“LG G5 外殼使用了 LM201b 鋁金屬專利設計，如果有油漆也能被指非全金屬，那麼飛機都不能稱作是金屬製！”
也就是說，JerryRigEverything刮下來的並不是真的塑料，而是一層厚厚的底漆，上面覆蓋有油漆。
除了隱藏掉天線條之外，這個塗層還為LG G5提供了溫和、柔軟的觸感，
而不是像其它金屬手機那樣保持了金屬的手感，你喜歡LG的這種處理方式嗎？
