Faber-Castell PITT Artist Pen Set (Blue/Green Pens) ASSORTED BLUE AND GREEN COLORS FOR WRITING - Use a variety of colors to add visual interest to your writing and fine detail pieces. Blue and Green colors included: #110 Phthalo Blue, #156 Cobalt Green, #170 May Green and #247 Indanthrene Blue. FINE DETAIL NIBS - The Superfine nib is a 0.4mm nib perfect for handwriting and detailing. HIGH QUALITY INK - Features 4 vibrant India Ink pens that are archival, waterproof, permanent, acid-free, lightfast and odorless. India Ink allows images in most colors to last in excess of 25 years! WORKS ON A VARIETY OF SURFACES - Premium India Ink will not bleed through your pages and the colors can be layered on paper, canvas, books, bibles, or journals. FABER-CASTELL QUALITY ART MATERIALS - See your artwork come to life with the absolute best quality art materials. Faber-Castell been a creator of quality art materials since 1761.