Markers
You can see/purchase markers at Utrecht Art Supplies
Markers are a very new medium, comparatively speaking, and have been traditionally used by children, graphic designers and cartoonists but other artists have been pushing the boundaries with this media also. Fine artists, tag artists and craft artists create awesome pieces using just markers (see contemporary artists at bottom of page).
There are many types of markers including water-, solvent- and alcohol-based as well as acrylic paint markers. All share the convenience of applying the media with a wick (or nib) enclosed in a metal, glass or plastic case. There is some concern about the toxicity of non-water based markers (see links below) so they should be always be used with adequate ventilation. Non-water-based markers are not appropriate for small children.
Environmental Health: Schools, The Perils of Permanent Marking Pens
Artist's Network: Learning How to Draw with Markers and Ink
Some general sites about the marker medium:
Just Some Markers
Nathalie's Studio:My Favorite Mixed Media Essentials: Markers & Pens
Liquitex Paint Markers
Water-based markers are used by children and elementary art educators due to their vibrant colors and ease of application. They are great for teaching about color and the wide range of colors available make them ideal for many different subjects.
A kindergarten portrait
Here is a great tutorial about what to do with dried up water-based markers:
Crafting Green World: Watercolors from Dried Up Markers
Professional grade markers are abudant, both water- and alcohol-based. There are many available brands of professional grade markers, including Prismacolor, Copic and Chartpak. These markers come in many colors but can also be layered, blended and mixed much like watercolor.
Here are some web sites and videos about how to use markers:
The Virtual Instructor: Markers
(the next one is a sight that sells markers but includes some good tips also)
Art Supply: Art Pens and Markers
Marker Love: Deviant Art
Harrington College of Design Art 101 Using Markers Vimeo video
The Best Copic Marker Tutorial Videos for Beginners
Prismacolor Art Markers Tips & Techniques YouTube video
Some contemporary artists who use markers:
BuzzFeed: Heike Weber
Art van Leeuwen
Gwenn Seemel
Some interesting sites showing art work created with markers:
Sharpie: Tag Art
Tumbler: Marker Art
Pinterest: Marker Art