I work as an optician and I was looking for a pen that could leave a readable mark on the new hydrophobic no glare coating on eyeglass lenses. These work exceptionally well and are easy to clean off afterwards when removed immediately. Great product!
They bleed trough the paper. Not a smooth writing pen. On removing the cap off one of the pens the pen nib and ink cartridge came off with the cap. They just not what I was looking for but again for the price they were ok.