Techniques for sketch-like "colouring in" in vector format

[lineweight]

I often create illustrations in a style where I have linework on one layer, and then block colours on another layer behind it. The block colours roughly - but deliberately not precisely - "colour in" the linework shapes. So for example if I draw a tree like this, using the vector pencil tool:

I can later add some colour like this:

 

That colour is just some very simple polygonal blocks drawn with the pen tool. No stroke, and my desired fill colour. This suits the drawing style I often want to achieve, and it also keeps the file pretty lightweight because the colour shapes don't have any curves. They are also quite easily edited - I can pick up and stretch their corners around.

Also, I can scale the whole image whilst keeping the linework line thickness the same relative to the page, while the colour blocks stay in the right place. For example, I can choose to scale that tree into a bigger one, but the thickness of the linework in the two trees remains the same:

 

This all works pretty well for the kind of illustrations I often want to do. I like to keep it all as vector objects to keep it clean and so that it's easy to edit and alter.

What I don't really like though is the process of drawing those colour blocks. I use the pen tool to click at a number of points to define the shape but this doesn't feel much like natural drawing. For example, this:

 

Is an intermediate step towards creating the final shape I want:

And in the intermediate step the fill is overlapping itself which is not an intuitive preview of what I'm going to end up with. In this example it's not too complicated, but there are other more complex fill shapes that I want to draw where it becomes confusing.

What I'd really like, is to be able to colour those shapes in like I might on paper with a marker pen or pencil. Of course I could do this with raster tools, but that seems an inefficient way to do it, and I think that would cause me image quality problems if I subsequently scaled them up (I'd want the edges of the colour fill areas to remain sharp and clean, not seen as scaled-up pixels).

I realise I can do something like this with the "vector brush" tool - it is quite satisfying and natural to draw, and gives me a result I'm happy with:

However, it doesn't survive scaling-up so well:

 

In addition, I'd worry that shading in a lot of areas like this would end up creating a file that would be heavy/slow to work on. And...it doesn't create a 'blob' of colour that can be easily edited/extended retrospectively.

 

My question, which may be a vit vague, is whether there is some other method of doing this kind of drawing, that I've not thought of.

Any suggestions welcome!

 

 

[Alfred]

3 minutes ago, lineweight said:

What I don't really like though is the process of drawing those colour blocks. I use the pen tool to click at a number of points to define the shape but this doesn't feel much like natural drawing.

Can you use the Pencil Tool instead, or do you particularly want to end up with a polygonal outline for each block of colour?

4 minutes ago, lineweight said:

[a vector brush stroke] doesn't survive scaling-up so well

Go to the Stroke panel and put a tick in the ‘Scale with object’ checkbox.

[lineweight]

13 minutes ago, Alfred said:

Can you use the Pencil Tool instead, or do you particularly want to end up with a polygonal outline for each block of colour?

Yes, in fact I've just now been playing with using the pencil tool instead.

I don't necessarily want to end up with a polygonal outline so it's possible I could just draw the outline with the pencil tool.

This has the advantage that when I have drawn each shape, I can move straight onto the next one with no extra clicks, whereas the pen tool is a bit annoying in that you have to double click to place the final vertex.

It still has the feature that the "preview" of the finished, filled shape can be a bit odd as I draw it but perhaps this is just inevitable.

[lineweight]

22 minutes ago, Alfred said:

Go to the Stroke panel and put a tick in the ‘Scale with object’ checkbox.

Thanks - this is useful.

This setting seems to be remembered when I use "synchronise with defaults" to pick up attributes from already existing objects, so it seems that it would not be too tricky to manage a drawing such that the 'linework' curves did not 'scale with object' but the fill ones would.

[thomaso]

52 minutes ago, lineweight said:

What I don't really like though is the process of drawing those colour blocks. I use the pen tool to click at a number of points to define the shape but this doesn't feel much like natural drawing.

What makes you think that this kind of colouring would/should feel like drawing?

Doesn't it look more like cut paper, maybe colored tracing paper, cut with scissors or a knife, applied on black borders? In this sense, the digital process of setting only points where the cut-out shape changes direction to produce only straight lines feels more natural and is in keeping with the analogue technique. But even curved lines set with bezier handles can also feel more like cutting than drawing.

[lineweight]

2 hours ago, thomaso said:

What makes you think that this kind of colouring would/should feel like drawing?

Doesn't it look more like cut paper, maybe colored tracing paper, cut with scissors or a knife, applied on black borders? In this sense, the digital process of setting only points where the cut-out shape changes direction to produce only straight lines feels more natural and is in keeping with the analogue technique. But even curved lines set with bezier handles can also feel more like cutting than drawing.

I get what you mean and it maybe looks a bit like that as a result of the method I am using... but really what I'd like it to 'feel' like is more like a combination of ink lines and marker pen or watercolour colouring. Of course it can never be exactly like that... or if I really wanted it to have that look I should probably be doing it as raster type work instead - but I'd like it to feel a bit more like that while I'm working on stuff just because that's what seems most natural. This is an extract from the kind of illustration I end up with using this method -