Pigment Ink (fast drying)
Example: VersaFine by Tsukineko
Fast drying on porous surfaces and embossable on coated surfaces. Water-resistant when dry. These ink pads are intended to last longer than solvent-based and water-based ink pads. Great for use when stamping very detailed designs. (My personal favorite).
Pigment Ink (opaque, pearlescent, chalk, metallic)
Example: VersaMagic or Brilliance by Tsukinkeko, ColorBox Chalk, Encor Metallic
Air dries, even on vellum. Intended for stamping on papers, shrink plastic, polymer clay, wood and leather. Can be used on both light and dark papers.
Dye-Based (Waterproof) Ink Pads
Example: Archival Ink by Ranger, Memento
These inks will not run with water on standard papers. May not dry on glossy surfaces. Once your stamped image is dry, you can add color with markers or watercolor pencils. Requires solvent-based cleaner to clean rubber stamps.
Dye-Based (non-permanent) Ink Pads
Example: Adirondack by Ranger
Used to create watercolor effects. Extensive color palette choices for this brand.
Solvent Ink Pads
Example: StazOn by Tsukineko
Permanent ink for stamping on just about any surface: wood, metal, glass, plastic, and specialty papers. Dries extremely fast. If you get it on your skin, it's like marking yourself with a Sharpie... doesn't come off for quite a while. Great for when stamping lots of duplicates. Requires solvent based cleaner. (My 2nd most favorite ink to use).
Fabric Ink Pads
Example: VersaCraft by Tsukineko
Pigment ink, requires heat setting to make permanent. Used for wood or fabric stamping. If you make an error when stamping, wash your shirt and impression will come out (before heat setting).
Washable or Tattoo Ink Pads
As the name implies, these inks will wash out easily and are often used with kids' crafting. Tattoo or Henna ink pads will dry on skin and may last for several days.
Example: VersaMark by Tsukineko
These ink pads are available in a variety of colors or clear and are mainly used when embossing (adding powder, then heat setting to create raised surface). Every crafter has at lease one of these in their supplies.
After reading this, choosing an ink pad for your next project will be easy! Remember to always use acid-free and archival if using for scrapbooking and journaling.
All ink pads sold in the craft section online or in a store are raised felt. This means the pad sits above the case which makes it easy to to ink any sized rubber stamp. The raised felt also makes it easy to re-ink when the pad starts running dry.
Full sized ink pads usually measure about 3" x 1.75". The smaller petal-shaped ink pads are much smaller at 1.5" x 1" but the shape of the petal allows you to ink tight areas. A benefit to their small size is that you're able to ink a stamp with more than one color. The oversized ink pads, measure anywhere from 4.25" x 6.25" to 5" x 6.75".
Most major brand ink pads offer re-inkers so if you know you're going to be stamping a large volume in one color, go ahead and buy the matching re-inker; it will save you $$$. Happy stamping, everyone!
Information gathered for this post is based on personal experience, customer feedback and online reviews. More to come about markers, watercolor pencils and pigment sticks you can use with rubber stamps.