So I can't seem to do line weight, I don't know how to go about it or anything. I was hoping that someone could point me to somewhere that would show how to do line weight. Or maybe its something you have to learn on your own?
Umm, press harder for thicker lines, lighter for lighter lines? And then, if you want, you can use lighter/darker lines to show volume, I think Elwell did a post on rules for edges here. As for expressiveness, I think you just end up doing that by yourself, no right or wrong way for that.
Shadow side lines thicker and darker light side lines thinner lighter is the rule of thumb and then add accents to pull your eye around to things you want to emphasize. Look at this Frazetta Notice how toward the light the line disappears or gets thin and toward the shadow they thicken. He ignores the rule when he wants to turn an edge like on the one skull.
In Deborah Rockman's book, "Drawing Essentials", she dedicates a whole section to the issue of line weight (aka line variation and sensitivity). You should try the local library to see if they have this book, or ask your parents for $$$. It's worth it, and comes with examples showing line weight.
Here's some stuff that I pull out from my mind based on what I read in the book. These are guidelines as to when to use line variation:
1) Light and shadow: Those edges or part of the subject that are bath in bright light should be drawn with thinner, lighter lines compared to the other parts of the subject.
2) Weight: Those edges that are "heavier" should be drawn with a darker, thicker line.
3) Surface tension I: For those edges that are in contact with the surface it is resting on, those edges should be drawn with a darker, thicker line (e.g: if a cube is resting on my laps, then those edges where the base of the cube and my laps meet, should be draw with thicker and darker to indicate that it is not some weightless feather)
4) Surface tension II : For those edges that are being "stretched" or "thinned", they should be drawn with a lighter, thinner line (e.g: if I'm bending my knee and the flesh of my knee stretches against the bones of the knee, then the edges of the knee should be drawn with a thinner lighter line).
5) Degree of importance: Say, you've 3 still life objects. The one in the foreground should be drawn darkest and the one in the further-most back should be drawn lighter to imply depth.
6) Movement / Speed of contours: Imagine you're a tiny ant moving along the contour of a large subject (ant moving along the contours of a 18-wheel truck). Those contours that are straight or simple should be drawn with light lines, and those that have complex curves and sudden changes in directions should be drawn with darker lines (e.g: the edges of the shaft of a gun should be drawn with light lines, while the trigger part of the gun should be drawn slightly darker).
7) Points of intersection: In a subject, those points of intersections, where one edge meets another, should be drawn with darker lines.
I hope that helps. The book explains in a much clearer manner, though.
Thanks for all of the replys guys I will be try some stuff out. One thing that I seem to have a problem with is making it looks good like, when I do it, it looks weird. I guess you could say (to me anyways) it looks akward (then again with a light source not established, it could be the cause of the problem)
1) practice drawing and applying the above knowledge
2) observe which areas of the drawing are successful and which are less successful.
3) figure out why and think about what you would do differently.
repeat repeat repeat...
and be sure to post your stuff and get feedback or redlines!