|Staedtler Triplus Fineliners|
That being said, there are many reasons to prefer markers over pencils: they have more vibrant colors, they can be used to cover large areas quickly and they are easier on your wrists/eyes/arms than pencils. So if your chosen coloring book has pictures on one side only or has thick enough paper to take pens/markers, by all means go for it!
Always test pens and markers at the back of the book before starting a picture.
Types of Markers
There are two types of markers you can get - alcohol based or water based pens. There are expensive and cheap brands in both types so feel free to experiment. Water based markers are less likely to bleed through books and are extremely blendable while alcohol ones will almost certainly bleed through everything out there. On the other hand, they are easier to work with and aren't as 'streaky' as water based markers.
Copics are the best and most expensive alcohol based markers but remember they're also refillable, so they work out cheaper in the long run. You may want to build up your collection a few pens at a time though. Other brands to check out are Tombow, Prismacolor and Touch Twin markers. Faber castell Pitt pens are also an option but they are NOT refillable and the India ink is permanent once dry.
The most popular brands are Staedtler and Stabilo. They look and work like regular pens but with fine points (.3 mm or so) to get into the really small areas some coloring books seem to specialize in. They work well with pencils so you can use them in the same picture for the intricate details. I have the Staedtler 36 pens set which comes with a few neons but the 20 set should be adequate for most pages. They tend to leave streaks if you try them in larger areas, I'd recommend markers for wide coverage instead.
this one. Colorists seem to agree that gel pens from Sakura are very good when it comes to price, color, coverage and even flow. Sakura Gelly rolls come in packs such as Moonlight, Souffle and Stardust with no repeats. So you can build up a collection of your favorite shades slowly.
I don't have much as much experience with pens and markers so I cannot really make personal recommendations but here are a few brands to get you started:
- Markers: Copics or Tombow
- Pens: Stabilo or Staedtler
- Gel pens: Sakura gelly roll