isolating line art

[serhc]

I'm a total noob at photoshop, and lately I've been taking the long way around doing things. So, I was wondering: is there a way to make white background, or any other flatly colored background invisible?

I want to isolate the black lines of a sketch, but I'd really rather not going around erasing everything.

The sketch I'm planning to worth with is attached below (still going to fiddle with the canvas size) - so yeah, is there a quick way to do this in ps?

[Grief]

in the future try working on multiple layers.
after you create a new file, make a new layer and start scribbling away on it.

theres several ways of getting rid of the white from an existing layer.

heres a sloppy method to erasing just the white. as a note, always work in at least 300 resolution.

http://img.photobucket.com/albums/v707/photou1/tut.png
alright so we have a line drawing on a white background. i made it a viking as to fit in with the usual CA motif.
i scaled these images down so that you wouldnt have to scroll like a madman to see what's going on. this isnt too difficult so you should see enough.
click the magic wand tool. it'll automatically create a lasso around contours of an area. the 'area' is defined by tonality which can be adjusted with the tolerance (see up on the toolbar where it says tolerance?, yeah well if the magic wand is 'grabbing' too much grey or not enough, you can adjust it here)
now you could hold shift and continue clicking every area you want selected 9all the areas of white), but thats tedious.

http://img.photobucket.com/albums/v707/photou1/tut2.png
instead unlick the continuous box up top. this will make the magic wand tool select all values on the canvas which are the same as the selected section you clicked (i.e. it'll lasso all the white areas for you).

http://img.photobucket.com/albums/v707/photou1/tut3.png
now before we can grab an eraser and get rid of all the nasty white, we need to unlock the layer. by default the initial layer is 'fixed' so that it is opaque, however if we create this as a layer it'll unlock it allowing us to alrer its original properties. (just double click it, then click okay on the new layer window that comes up)

http://img.photobucket.com/albums/v707/photou1/tut4.png
now we can grab the eraser and go to town leaving the line art intact. neato burrito.
but now you have that checkered transparent background which is hard to work on visually.

http://img.photobucket.com/albums/v707/photou1/tut5.png
let's create a new layer and put it under the line-art so we can see.
simply click the 'new layer button', now we need to fill it in.
you can use the paint bucket (its hidden under the gradient tool) and simply fill the canvas this way.
or if you want to learn to do things the quick way press "CTRL ALT BACKSPACE" to automatically fill the active layer with white
(CTRL BACKSPACE is the auto black fill)

well there you go.
___________________

[edit] why do you need to get rid of the white anyway? there's really no purpose to getting rid of it if you learn to use the layers in an additive fashion.
i think these two words are the key to you making a giant leap in photoshop: multiply layer.

[serhc]

Thanks for taking the time to do all that Grief, really appreciate it.

My reason for wanting to get rid of the white under the line art...I suppose it's because I'm really no good at rendering, and I just wanted to slip some color underneath the lines to create some atmosphere.

But...what's this multiply layer thing you speak of? Is it just what you said, using layers in an additive fashion?

[Grief]

it makes the layer transparent based on tonality.

darker values will 'show through' the multiply layer (such as white areas), which allows exactly as you described, to color on a layer underneath and still have the darker linework remain on top.

two options to solve your problem:

- create a new layer, put it under your line-art. set your line-art to multiply and color 'under' the drawing.

or

- keep your line-art on the bottom and create a new layer on top. set the new layer on top as the multiply layer. color the top layer.

[Flake]

There's yet another way to do it using the channels in PS, Bluefooted explains it in these tutorials.

http://www.conceptart.org/forums/showthread.php?t=46462
http://www.conceptart.org/forums/showthread.php?t=110509

[Killer Napkins]

i was about to say... multiply is the easiest way to do it... with all your line art on one layer then set the layer properties to multiply then draw on layers underneath the line art

[serhc]

Awesome, thanks guys, this makes my life a LOT easier. :P I've always wondered why photoshop didn't have cool blending options, but I just didn't know about them, haha...

Maybe I'll take a good read through the ps tutorial here again

[Evil_Sloth]

this is a pimpen technique, best used for scanned pencil drawings cause as has been said if you drawing in PS you just use another layer for line art.

duplicate the sketch layer

select all and copy

click the mask icon

alt or option (mac) click the mask of the duplicated layer

paste the sketch into it

invert it

apply the mask

turn on lock transparent pixels

fill it with pure black

done.

add a layer below and fill it with pure white to see the results.

one big advantage that this has over multiply is that you can colour your line art by simply painting it onto the locked pixel line are layer.

http://img153.imageshack.us/img153/5720/step1hu4.jpg
http://img206.imageshack.us/img206/6518/step2rc9.jpg
http://img258.imageshack.us/img258/184/step3nl9.jpg