Then can you elaborate more please?
Sure. If you look at the post, its almost 3 years old. Since then I've continued to improved my art skill and knowledge. I have new theories and ways of explaining. I assume since you are in this post that you want a better explanation about tracing art and how to make it look good.
When tracing art, you are basically trying to achieve 2 goals: to make an image look drawn, and to make an art piece quickly.
When it comes to drawn art, there are many different ways to measure and describe what makes a piece looks good, which is the core of this post, asking if it is ok to trace art and if it looks good. The main thing I would considered trying to have a discussion about how good a piece of art look is learning to understand the quirks of the brain. What tricks it into thinking something looks good, and what tricks it into thinking something looks wrong?
Now, I could go into a whole theory and write up on just the subject of mental tricks art use to look good, which are issues that come up with traced art. I won't go into too much because I do have a bad habit of writing walls of text, but I'll get to the point I was trying to make in my initial reply.
One of the core brain tricks to know is how the brain tries to identify parts of the body. Because 2D art removes a lot of the details and clues (aka the image looks flat without any shading), we have to use other tricks to help with making the art 'readable.' And one simple way to do this is to think of art in terms of silhouettes. That is to say, if you just paint the character solid black, what do you see? I actually found that it is more than this. A good readable 2D draw is one that you can paint black, and then shrink down. If you shrink the character down, or move far away enough from the screen that the character is no bigger than your thumb when you stick your arm forward (think of how painters will uses their thumb to measure a subject while they are painting). If you can see this shrunken down no detail version of your character, and still be able to easily see who they are and what they are doing, then you art will be able to catch anyone's eye if they are just quickly browsing by.
Doing this trick basically introduces people to ideas on how to make a character more readable, which mainly focuses one 2 things, how to clean up an image, and how to exaggerate an image. After doing just the big picture (whole body) idea, you can do the same thing to parts of the body. In my initial reply, I skipped over some details, one of them is that I said
first painting over the initial image (after say, photoshopping body parts and the pose to what you want),
I said photoshopping the body. This is one trick I've used where I take a final image, say of a 3D model I rendered, and I'll paint the character all black, lean away from the screen and see if the characters still look unique, distinguishable, and if I can easily tell if they are still easy to understand what they are trying to do (is it obvious or not, an erotic pose needs to be obviously erotic for 2D art to be easy to read, even if the character is shy or not doing it on purpose). And then I hinted at the next step, where instead of painting the hole body black, you paint each part of the body different hues of a light color (light purple, light green, light blue). Doing so allows for a more advance version of this, where with the body parts being different collors it is easy to see how they overlap (a detail you won't be able to see when everything is just painted black).
while I haven't elaborated on the tricks of the brain, I will say this, the brain likes to simplify. Sure the brain is advance, it will use subtle clues to give it the information it needs (such as how it uses shading to get a 3D understand of 2D objects). But I will say this, silhouettes are the most powerful because that's how the brain likes to reduce and simply the data for easy processing. Sure, there is a silhouettes for the body and head, but there can also be silhouettes for different parts of the body, as a way for the brain to piece together information. I think the most common example I see is the rib cage, if you just paint the rib cage on a lot of people, just on the shape of the rib cage alone, you will notice 2 things. first you will notice that there are good rib cages and bad ribcages. a bad ribcage is just a blob and you can't really find anything meaningful about the image. However a good rib cage is different. the second thing you will notice is that with the right image (a good rib cage) you can actually get a feeling of what the body is doing. Mainly, the only thing you will notice is if you can tell it is a torso, and you can tell which way the torso is turned. is it facing up, or bent over, is it turned to the side, or tipping over? Very rarely you will get a 3D sense from just the 2D image, but if you can start hinting at it with just the silhouette you'll find that it makes the final artwork very readable.
The reason I suggest painting all the body parts is to see if it looks readable. What 2D artist will often do instead is actually draw lines to communicate the 3D nature of what they are trynig to achieve. I find that while this is good, it is hard to do until you have a good 3D understanding of things, and you only really need it if you are messing with perspective drawing or plan to shade the character and you need a good 3D sense before you move to the next step. But if you are just tracing art, that this does is by seeing teh boundries between body parts, it can help you with trying to place lines that aren't in a photo, but lines that will help separate the body. ie: it is good to have a bit of the inner thigh or under arm look like it is covering up part of the body where it connects, so that it looks like the leg continues to be come part of the body, rather than just stopping and merging into a blob that is the whole body.
From this point, I'd have to use images, but it depends on what you were really asking for when you asked for an elaboration. But this is the main points of my reply.
I also hint at thicker lines and smoother simpler lines, due to again how the brain can be tricked. how to simplify based on knowing what the brain will get caught up on (you don't want a lot of details or small curves in your line as the brain will get stuck on those and start to get uncomfortable), but as I said, a lot of this is based on a more fundamental theory on how the brain interacts with 2D art and knowing the tricks, but it's a whole other write up for another time.
