Soft core for easy spreading. The thicker core can be used for even, solid application, while the thinner core can be used for smooth, fine line drawing. Excellent lightfastness High-grade pigments are carefully selected to minimize fading and discoloration due to light. Easy to draw with a thick core and a thick shaft. The core is 3.8mm in diameter and thick enough to fill a large area at a time. The 7.8mm-diameter barrel is easy to hold and does not tire the hand. Can be painted over watercolors, gouache, and acrylics. Fixes well on any paper and can be used with watercolors and acrylics. Can be painted in watercolor style with Merz If you draw on the screen with colored pencils in advance and then dissolve and blur over it with “Merz”, you can get a watercolor finish. All my products are 100% Authentic. International Buyers – Please Note. I do not mark merchandise values below value or mark items as “gifts” – US and International government regulations prohibit such behavior.