Sketchy Style Comics

[curlyfuandpeanuts]

If you look at something like Corto Maltes by Hugo Pratt, you can see how a great artist dealt with sketchy art. Although maybe it is more "scratchy" because sometimes you can almost hear the nib of the pen scratching along the paper. If you look at how he draws beards, it can be simply a few brushes of ink. When he draws water it can almost become abstract.
Of course that might be more to do with being free with your pen rather than being deliberately sketchy.

[TristanJensen]

Actually one of my favorite webcomics is Extra Ordinary (exocomics.com) which is drawn in pencil (whether its "sketchy" is up to debate)

[johndanims]

You could no doubt say my Working Doodles comic is sketchy. It may or may not be everyone's style but due to the nature of the idea behind it I try and keep it as raw looking as possible. I've had comments in the past from people wanting me to clean up the scans and make it look a little less raw but I think that would take away from what it's meant to be. If I ever get round to doing any other comics they would definitely be a lot more cleaner.

I did originally have the idea of not having the border round it and putting a little drop shadow round it when scanning them in but decided to scrap that idea before going forward with posting them as it would look good on sites with one set background but as I post it on a few different places I figured that I needed something a bit more universal so stuck with the black border. If I was posting it on one solid location I'd consider doing that in the future though.

[Waterdrain]

I guess it really all depends on what the comic is like, sometimes the sketchy look can be really charming, especially when has a nice loose style to it. As long as the sketches are constant, instead of heavy lines in some places and light ones in others, it won't come off as messy. Otherwise readers might be confused about what to focus on the page.

[juniorguilherme340]

My own comic when i first started use to be very scketchy according to some, and i do think so myself, now its a bit finer

http://tapastic.com/series/Acroalis

[monotone_ink]

Sketchiness really depends on how its executed, and whether it fits the tone of the story or not. I chose to make the art for Shade sketchy because I knew it was going to be a dark story with extremely intense fight scenes.

Here's a manga that uses its sketchiness to its own advantage - being a story that deals with genocide, cannibalism and a never ending conflict between two very similar species, the art style conveys the story well.
I think that in order for the sketchy style to look good, the artist should 'know what they're doing': knowing the basics and general construction.
As seen from the example manga, the artist has a good sense of shape, lighting, shading, composition, anatomy, stylistic sense, all the necessary skills to make the page look good.