Many times it's not until the end of drawing when we notice a mistake that was there from the start. It's very, very frustrating to see it ruin our whole work. If only there was a way to fix it at this point...
This is going to be a controversial tutorial to many, a tutorial about cheating. After all, art is about effort, about making people jealous of some skill. That's why digital art is often despised—because the computer does it all for you!
I'm not going to argue about the definition of art—I did it enough in many of my articles. If you do have a promising traditional drawing that needs some fixes, and you don't think it will make your work less valuable, I can show you how to use Photoshop for this purpose. You don't need any previous experience with this software—I'll lead you through step by step!
Disclaimer: this tutorial is about making a traditional artwork look better. If you want to make your scan look just as good as it looked before scanning, Clean Up Your Traditional Drawings in Photoshop will be a better choice for you.
Before we start, scan/photograph your drawing and clean it up, if necessary. You can use the tutorial from the link above, but ignore the last steps.
1. Move a Part
Sometimes a part of the drawing ends up in a place it was never supposed to be. You could try to erase it and draw it anew, but the trace of this fix will stay. Let's check another method.
Select the area you want to move with the Lasso Tool (L).
Use the Move Tool (V) to drag the area where it belongs. Deselect (Control-D).
2. Patch a Mistake
We've moved the part, but the change is too visible. We need to use another tool to fix it.
Select the area you want to fix with the Patch Tool (J) (it's on the same list as the Spot Healing Brush).
Drag the area to a place you want to "borrow".
Use the Patch Tool in as many places as necessary to make the "scar" less obvious.
3. Erase a Mistake
This seems very easy, but using the wrong eraser may lead to a visibly fake effect like below:
To avoid this effect, go to Window > Tool Presets. Grab the Eraser Tool (E) and select the Pencil Eraser from the list.
Use it as before. If you want to make the eraser gentler without a tablet, change its Opacity.
The difference is subtle, but very important for the overall effect:
4. Resize a Part
Resizing a part of a picture is tricky, because it's rarely independent from the rest.
Duplicate the layer (Control-J), then hide it (click the eye next to it). Select the area with the Lasso Tool (L).
Go to Edit > Free Transform or press Control-T. Switch to Warp Mode.
Drag the points closer to the middle to scale the part down, or far from the middle to scale it up. If something goes wrong, just press Escape and try again.
Again, we need to conceal any trace of the modification. We could patch the crack between the resized area and the rest of the picture, but there's an easier way. Show the duplicate you've created before and put a Layer Mask on it. Fill it with black, and then reveal only the part right above the crack.
If you have no idea what I'm talking about, try this very quick tutorial about using Layer Masks.
The difference is stunning!
5. Reshape a Part
The same tool can be used when you want to change the shape of a part:
If you want more control over it, there's another tool you can use, a very powerful one:
Go to Filter > Liquify or use the shortcut Control-Shift-X.
Use the Forward Warp Tool (W) to reshape the chosen parts. The larger the brush, the more natural the effect. Be careful: in this mode you can undo only one change!
This tool lets you make spectacular changes!
6. Shade the Drawing
Those modifications were mostly about fixing the shape of the character. Now we're going to try some more advanced ones—about adding something to the drawing. The more you use them, the more obvious it will be that the drawing was modified digitally, but sometimes the effect is worth it.
Duplicate the layer (Control-J) and work on the copy, leaving the original below. Go into Quick Mask Mode (Q). Grab a soft brush and select the areas you'd like to darken.
Go out of Quick Mask Mode (Q). Invert the selection (Control-Shift-I). Go to Image > Adjustment > Hue/Saturation and drop the Lightness.
Use the same eraser as before to erase the shadow outside the body.
Now use the same eraser to "blend" the shadow. It shouldn't be that uniform; make it ragged.
As you can see, this modification is pretty drastic, so use it sparingly. The smaller the final drawing, the easier it will be for you to get away with it.
7. Add a Glossy Effect
This effect works only if the object is drawn as dark. In my case I'll need to darken it all. Create a New Layer (Control-Alt-Shift-N) and fill it with black using the Paint Bucket Tool (G). Lower the Opacity of this layer.
Go into Quick Mask Mode (Q) and paint the areas you want shiny with a soft brush.
Go out of the Quick Mask Mode (Q), and invert the selection (Control-Shift-I). Click the main layer and duplicate the selected area (Control-J). Drag it above the darkening layer.
Use the same technique as with the shadow to blend the lighting.
To make the effect subtler, lower the Opacity of the layer.
8. Add a Blur
Warning: this effect is very digital in look!
Go into the Quick Mask Mode (Q) and paint the border of the object with a soft brush.
Go out of the mode (Q) and invert the selection (Control-Shift-I). Go to Filter > Blur > Gaussian Blur.
Be very careful here—it's easy to overdo this effect!
9. Sharpen the Drawing
To make the lines clearer, even though they're very blurry in the original, you can use Filter > Sharpen > Smart Sharpen.
10. Add a Paper Effect
This is the most popular and the most "innocent" enhancing trick. Paste the paper texture below the drawing. Change the Blend Mode of the drawing to Multiply.
Right click the layers and select Flatten Image. Then go to Filter > Filter Gallery. Select Texturizer from the Texture set, and adjust the options to your liking.
Last, but not least, you can use Levels (Control-L) to adjust the brightness of the whole picture.
That Would Be All!
As you can see, there are many ways to fix your artwork, and even enhance it. You don't need to use them all—feel free to pick only those that really make your work look as awesome as intended.
Finally, I must warn you. Even if you consider it fixing, not cheating, make sure you treat it as a final touching up, not as another phase of creation. The more different the final effect from the original, the further it will go from a traditional art. Which is not "wrong", of course, as long as you're honest with yourself and others!