Pentel EnerGel Liquid Gel Pens, Medium Line, Metal Tip, Assorted Ink, 4-Pack. High performance ink technology combines the best qualities of liquid and gel ink for a super-smooth writing experience. Pack includes: black, red, blue and green ink colored EnerGel pens. Pentel gel pens do not bleed through most standard paper - great for adult coloring books. Liquid gel ink dries fast, even left-handed writers love it - no smears, no smudges, no globs just smooth writing.