"碳素笔"和"中性笔"用英语怎么说??

"碳素笔"可以说成"Carbon Pen",口语中也有说成"black pen"

碳素笔""Carbon Pen",可以看看这里的应用:)~
http://www.wanfangdata.com.cn/qikan/periodical.articles/gpxygpfx/gpxy99/gpxy9905/990515.htm

中性笔是:(Gel-ink pen)
或者"中性笔"Neutral water pen

还有:
圆珠笔(Ball pen)/ball-point pen.
马克笔(Marker pen)

碳素笔water-based dyestuff ink pen
中性笔-gel ink pen

只知道中性笔：gel ink pen

Carbon Neutral