I sketch the concepts on newsprint papers where the background are not white. How can i deal with that ? Erase the background ?
Another question is i scan my drawing on normal paper, but it seems like it’s not white but kinda blue. And when i place those on Illustrator, it looks like it’s a block. How can i do ?
thx for any suggestions.
In Photoshop, adjust the Levels, or Color Balance, or Hue/Saturation. All 3 can be found in:
Image > Adjustments >
Your best bet for making the background white instead of “newsprint” colored is to use Levels:
It will bring up a box with 3 eyedroppers in it. Click on the white filled eyedropper and then click on the color in your scan that you want to be the whitest point. Everything “lighter” in value will become white…
You can adjust things with the sliders in the pop-up box as well…
You can get rid of the blue tones with Color Balance or Hue/Saturation. Both are in the pull down menus. Just play around with the sliders to see what happens.
Good luck!
Also, when you’re in photoshop, if you then take out the white parts to make it transparent, you won’t have the block in illustrator. It’ll keep the transparent parts clear as long as you use the photoshop file in illustrator and don’t convert to jpeg.
thx for ur replies…
I am now editing in photoshop…it’s really a big work!
I try to use “level” to change the background to white. Still u can see
some little dots there, but it’s much more better than before.
If your concepts are simple line drawings, you can also drop the scan into Illustrator and use live trace to convert it into vector shapes.
Once you have it where it looks good, hit the expand button and remove any parts that you don’t want like backgrounds or stray marks. You will be left with scalable vectors that you can manipulate in illustrator or drop back into photoshop.
It’s really nice because you can then output whatever size you want.
A few more tips:
-For the future, sketch on white paper…not on newsprint! 
-If you have some leftover dark spots, just paint over them with a white airbrush…
-Skinny brings up a good point too, and there’s another way to go about it which might help to keep the file sizes to a minumum: After placing the images in the Illustrator document, you can use the tranparency menu in Illustrator to make the white transparent by setting the object to “multiply” just like a layer in Photoshop
Didn’t know you could do that in illustrator. I’ll have to try that one out, thanx.
Yeah, in the transparency menu, there is a little pull down selection box set to normal by default, but it has screen, multiply, color burn… just like photoshop… handy.
I use AI10, the live trace is only in CS2. Is the any other solution i can use ?