Lip tutorial
I want to state, first, that every individual pair of lips is painted differently - because the light sources in paintings vary, the skin colours are different. The shapes of the lips are wildly different and the shape of the face surrounding the lips highly affect the appearance of the mouth. Having said that, this is much like my nose tutorial - just a little explanation on how I sometimes go about painting lips.
Step one - Light source and general shape
Since we're just doing the lips now and not giving a drat about the rest of the face, focus on where the light source is... and what the shape of the lips is. I'm picking a pair of pouty, full lips for this demonstration - because I can go wild with the highlights on a pair of lips like these.
Something some people seem to forget is that the line separating upper from lower lip is rarely 'straight'. The very shape of the lips is usually curvy and smoothly pillowed. I just love lips. Aside from the eyes, they're the most expressive part of any human as far as I'm concerned, and there is a whole lot of sensuality in the look of a mouth (be it thin-lipped or full-lipped or any shape and form - you can make any or none of these look very sensual and appealing). Picking the colour of the lips is easy for the most part. Without lipstick on the lips, you can just take the skin colour - make it a little darker and colder (more red, if you will, less yellow) and you'll be home free.
Step two - Thinking about surrounding shapes
Like I said previously, a lot of different factors play in when it comes to the looks of a pair of lips. Whatever else you're doing right now, do NOT paint in the red lines I've sketched on the picture. I just want to point out a few surrounding shapes that will highly affect the appearance of the mouth. The chin and the area right above it. The little dip just above the lips, and the lines (if any) leading from the nostrils down to the corner of the mouth. If you paint a pair of lips and you neglect shading the surrounding area, you'll get a pair of REALLY flat looking lips. They'll look stupidly pasted onto the face.
Step three - Finding the surrounding shapes
So, step three is a matter of shading. To make the lips pout, and for you to find the highlights and the shadows on the lips easier - it's a good thing to get the surrounding shading down here. This step makes such a huge difference that suddenly - without altering much about the lips themselves - what was just a couple of flattened-looking pink worms suddenly look like an appealing set of lips. What I did was to add massive shading to the left of the lips, to pick out a fine looking chin and deepen the dip above the lips. I only added a couple of bland highlights to the lips themselves (on the two 'pillows' on the bottom lip), and there's already a major difference. I'm using a slightly warmer (and of course lighter) colour for the highlighting on the lips at this point.
Step four - Softening the shapes and finding the lips
Here we're basically softening the sharp sketch-highlights and lines. There's a pair of fine lips hiding in the clumsy shading and I'm trying to find them. Where I've worked with big brushes with rather soft edges before, I now switch down to a smaller spackled brush or a hard edged medium sized brush and I use veeeery light pressure as I move from curve to curve with the colour picker ready to pick up every available colour for me.
It's a matter of blending and finding the right forms - the thing with a pair of full lips like theses is that there isn't really any sharpness to them. You'll not have sharp edges and crisp lines. Better get rid of those stark whatevers and find the soft and lush forms instead. I've also added some light additional shading where the upper lip will be tilting towards the teeth, and very discreetly, I've begun to pick out the shape and form.
Step five - Contrast! Fullness! Highlights!
So I've been all gentle and careful so far. Now I blast it with some more daring highlights and shadows - I'm really digging in to find the shape of the lips. Exaggerating, even, especially on the upper lip - I want that top lip to be pouting, I want it to feel fleshy and 'real'. I can see, looking at it, that the highlight there is way too bright for the lighting - but I'm going to leave it like that to refrain from forgetting about the shape I need to remember is there.
I've now found the perfect curve of the upper lip and it's in harmony with the bottom lip. I darkened the left side of the lip rather drastically - remembering my light source, again, and deciding that the tilt of the upper lip towards the teeth will make sure most of it is shadowed. The bottom lip doesn't catch as much shadow - it's a 'fluffier' pillow, more fleshed out.
Step six - Removal of unrealistic sketch-lines and details
Anything I sketched in to keep track of the shape is removed at this point. I simply paint over the unrealistic highlights I painted in on top of the upper lip in the very first step. I also remove the sketch lines that were defining the shape of the lips - if I've been doing my work so far, I don't really need them at this point. The lips should have a shape all of their own now. I should be able to see the fullness and the form of both upper and lower lip without any aiding lines. Instead of lines, I draw in a few shadows and more natural highlights. On these lips, I use a rather brown colour for the shadows rather than a more reddish tone if I'd been going for makeup.
Step seven - Further definition
At this point, I generally have a really good feel for what kind of lips I'm going for. If you study your lips in the mirror, you might notice that there are highlights not only on the lips themselves, but often around the surrounding area (and we should try to find those - especially if the look aimed for is of the sensual and voluptuous kind). Defining a pair of lips is both about adding shadows and adding highlights.
In this case, I further added to the shadowed part of the face, but I also went ahead and added more highlights above the upper lip as well as below the bottom, close to the corner of the mouth. I've found that this often adds to the 'glossy' feel of a pair of lips.... and there usually is a narrow edge of skin there that is part of the lips as far as the shape goes (slightly pouted, if you will) but doesn't have the same darker, more pink colour as the rest of the lips. This isn't necessary, but I'm doing it here - it's often a sign of a pair of very full lips. Furthermore, I'm doing something about the utterly ugly highlight at the peak of the upper lip - I remember that I should emphasise the shape there, but I use a mix of a more bland highlight and surrounding shadows to pick it out. I'm also defining the dent above the upper lip further - this also adds to a pair of convincing lips.
Step eight - Sharpening and redefining highlights
So, what did I do now? Well, I decided that the highlights looked boring and blurred. I decided I wanted the 'high point' of the bottom lip to be a bit further up. What I actually did was to take a sharp edged brush and very gently paint over the old highlights, and then I repainted sharper highlights with quick, sweeping motions. I used a mix of pink and (believe it or not) green and yellow to achieve the colour on the bottom lip's highlights. I used a colder shade of pink and a touch of blue for the top lips highlights? Why? I can't quite say - I felt like it. The upper lip is more coldly coloured if you take a closer look at it - I felt it demanded a colder coloured highlight.
Step nine - Definition, definition, definition
Did I already sharpen the highlights? Not nearly well enough! Thing is, lips are all soft curves and plump shapes, but I've always found that brighter highlights with occasional sharp (when compared to the much softer shadows and midtones) edges really make a pair of lips 'pop' (and I mean that in the good way, not the 'exploding silicone lips!!' way). In this step, I went over every single highlight and defined it further. I imagined the lines leading vertically over the lips and I picked out glossy lights reflecting on these.
Step ten - Texturing
So, among all these glossy highlights and smooth shadows, I've neglected any kind of texture to the lips. What needs to be done is to pick a small brush and then go over the lips like a madwoman - using the colour picker to snag colours from left and right - and 'prickle' the skin with a myriad of little dots and colour variations. Break the highlights up, bring some interesting variation to the shadows if you will. If you're having problems with the texturing the first time around, do a few textured, spackled brushes and apply them on a couple of different layers with the layers set to soft light and multiply.
Step eleven - Finishing off
There's little to say about the final step. When you finish the lips, you might end up deciding against some part of the shape you were previously very fond of. I decided, here, to shade the upper lip further - taking away a little from its plumpness but, I think, instead adding to mystery of this particular mouth. I add more texture, in particular to the more shaded parts - picking out a few highlights on the darker side of the bottom lip, for instance.
Mostly, the final step is just about looking at what you've done and deciding whether it's what you wanted or not. If not - I suppose you should have made any major changes in the earlier steps but it's never, ever too late to repaint, redo and remodel. Anyway, good luck with your lip-painting :) I hope I've been a little helpful.
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