Hello!
I'm a portuguese architecture student and I have drawing lessons at my university.
We are just beggining, despite I used to draw, in classes we have to do it like our teacher says and not like we are used to.
I'm trying to learn a bit more, we have started drawing a paper bag, then we added a paper box. After that we put the paper box inside a plastic bag and tied it up, then add a glass bottle. After all that we put a fabric covering the objects. The first support drawings they have given us were from Dom Bachardy and later on from Degas. My teacher told us we had to try to draw firstly like Dom Bachardy making a sum up of what we see and then like Degas trying to find the correct shape of the object.
My teacher says I still have to understand better what I see, the scale are good however I have to make a difference between substances (specially between the paper bag and the paper box). I still don't understand how can I draw a tied up plastic bag making the impression that it is really transparent.
I have just found this site and I find it really good. I've seen some lessons from the bigginers and I am trying to find some to use in my classes.
Could anyone give me some tips about it, please?
Thank you.

Vivianap, this sounds like a very standard procedure for learning in a drawing class and always quite interesting. It can be a bit challenging at first as your brain is trying to make you label objects and see them a different way.

However you need to learn to analyse what you see more carefully and push that analytical side of your brain to one side.

All objects, no matter what they are, are composed of areas of light and dark. That includes paper, cloth, glass, rocks, whatever. You need to teach yourself to closely observe the object and notice the subtle differences in values that give the object its unique appearance.

This is something that comes with experience and lots of drawing time. Take a simple study of a glass for instance or a crumpled piece of paper and draw it. Examine it closely, draw it in different mediums, different lighting and times of day.

There are no tricks, just light and dark and observational skills. You can do this. Try something simple and post it here and we'll see if we can head you in the right direction if you're having problems with it.

I'm sure you've heard this before but what you are doing when you draw or paint is "Translating" reality into pencil marks and brush stokes. Your instructors will try to get you to learn how to translate what you see into reconizable textures, shapes and values. The more we draw things the more we become familiar with these things and the better we can see them.

bob

I drew this for a challenge we had .. I guess you can tell what it is ...it was challenging to make the clear bag over the bread .

Good job. I might try that some time - if I can find the time.

This is what I keep drawing.
The paper and plastic marks are too dark, how can I say...I keep doing too much pressure with the pencils?
And yet I can't find the right way to make difference between the paper and the plastic.
You can see some sentences in my drawings (it's portuguese!) because my teacher wants us to criticise them (the different marks we use), we have to get the ability to know what we do wrong and write it down with the correct vocabulary and the right balance in the paper (what it's even worse because as a begginer I still don't know what are the correct marks).
I have to thank you for your kind support.
Thanks!

What you are doing are line drawings, and really very good ones; you're accurately drawing the shapes of all the objects in your scenes. But a line drawing really doesn't suggest any materials, because it's just lines. To have different materials, you need to use shading so that different areas have different values of light and dark. In the process of adding the shading, you would need to remove the outlines. For a shaded drawing, you can draw light outlines as a guide, but they're gone by the time the drawing is finished.

If you look at Kim's loaf of bread, there really aren't lines around the plastic and bread so much as there are shaded areas to suggest the bag and the slices.

I'd agree with Ernest. Your drawings are lovely - as line drawings. You do need to model your drawings to bring out the textures that you are looking for. Shade and light is what will give the images form and let the eye distinguish between plastic, glass or fabric.

While I personally love line drawings as they are clean and crisp, I know that they only render an object in a single dimension. Create shading to give your objects form and structure and the materials will create themselves.