... factory 2>No smelling,water based ink 3>OEM offered Invisible UV Pen Invisible UV Pen1>Tip 0.5,0.8mm,1.0&2.0mm ... smell and and no color! Writings are only visible under UV/black light!4> OEM service offeredThey have been exported ... Straight & Grading Ruler,Garment Ruler,Fashion Design Ruler,Fabric Marker Pen,Water erasable Marker,Permanent marker Pen,Textile Marker.etc Invisible UV Pen/ fabric marker