[Courses][gimp] Lesson 5: Basic Drawing Tools

Akkana Peck akkana at shallowsky.com
Fri Mar 4 16:25:19 EST 2005

Wow, some of you already do stuff I don't know how to do in gimp,
like making new brushes.  It's been really fun (as always) to
see everyone's homework projects!

Julie Sloan writes:
> Then I found a cat to lay on my stack of paper and used the freehand select 
> tool (and lots of "undo") to remove the previous background from around the 
> cat, and after lots of trial and error also removed the white background I 
> was left with.

Freehand select is hard to do accurantely, isn't it?  Fortunately there's
an easier way (Bezier select) -- I'll talk about that in Lesson 7.
It's easier because you connect-the-dots to make an outline, so
you can stop and take a breath and massage your cramped fingers.
(It's easier for other reasons, too.)

> I used the "select contiguous regions" wand thingie and 
> then select > invert while the white background was selected.
[ ... ]
> I have another cat who was on the refrigerator but I thought she would look 
> good on the monitor, so I repeated the process I used with the other cat... 
> but for some reason I can see stuff through her.  I don't know what I did 

I'm not sure why either.  But if you used "select contiguous regions" on
the second cat, it might be that some areas got partially selected.
She's already transparent by the time she shows up in the xcf --
I checked to see if the layer had gotten transparent, but that
wasn't it, so it must have been that for some reason she was only
partially selected before you copied her.

I'm also not sure how to make a partially transparent layer opaque
again.  I played with various operations and couldn't find an easy
way.  The best I found was to select the layer in the layers dialog,
go back to the image and Copy, then Edit->Paste as New, then in the
new image, do Image->Flatten Image.  That gets a cat with the right
color pattern, but with a white background.  Then
Layer->Transparency->Add Alpha Channel so the new image can do
transparency again, Select by Color to select the white background,
Clear, Copy, then paste back into the original image.

What a pain!  There must be a better way, but I couldn't find it.

> layer" button, which looks like two sheets of paper.  I duplicated the 
> monitor cat a couple of times and that darkened her up.  

But that's a clever workaround!  And a lot easier than my long method.

> I wanted a window, but when I pasted it into my picture it showed up in 
> front of the monitor.  so I clicked the eye to make it invisible and 
> duplicated that part of the monitor it was covering up, and pasted that as 
> a new layer.  I had to rearrange the layers so the window was right on top 
> of the background, then the monitor on top of that, then the cat (and her 
> duplicates) on the monitor.  I know I'm probably making this way too 
> complicated. 

Sometimes that's exactly what you have to do when you have two figures
intertwined: duplicate part of a layer and move it up or down in the
stack.  One thing you can do to make it a little easier is to use
one layer to select part of another layer.  For instance, in
I wanted the j and the m to intertwine.  So I put the j layer
(and its shadow) on top, and then on the layer with the m, I
used "select by color" or some similar tool to select the m,
then went back to the j layer and did Edit->Clear to cut that part out.
Alternately, I could have put the j underneath, used the m to select
the part of the j that needed to be on top, duplicated that part of
the j and made a new layer on top of the m.


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