Using Masks and Layers—Painting, Filling, and Color Tools - GIMP 2.6 for Photographers: Image Editing with Open Source Software - page 243

3.10.1 The Free Select Tool (Polygon Lasso) as a
Select Tool
The polygon lasso has been introduced to GIMP in version 2.6. You can cut out
image objects precisely along the contours and quickly extract constructed,
preferably straight forms. I'll show you how to use the polygon lasso in the
following section.
You must work cautiously when you are making a selection, and you
must adjust the settings when you are extracting a rounded form such as a
wine glass. Actually, GIMP has a tool better suited for these kinds of tasks -
the Paths tool . But you will notice that you can manage just as well with the
polygon lasso. Therefore, I will compare the two.
3.10.2 Extracting a Wine Glass with the Polygon
Lasso
The Procedure
• Open the image wineglass.png from the SampleImages folder on the DVD.
• Create a selection by outlining the wine glass with the Free Select tool in
polygon lasso mode .
• Give your selection a soft edge (feathering) of 3 px radius.
• Save your selection.
• Copy the wine glass with the command Edit > Copy and paste it as a new
layer ( Floating Selection > New Layer ) with the command Edit > Paste .
• Save the image as wineglass.xcf as an image with layers.
• Add a new layer under the layer with the wine glass: background .
• Colorize your background layer with a color of your choice.
• Erase some of the wine glass with a large and soft eraser ( Eraser tool ) with
an opacity of 10% to depict the transparency of the glass.
• Save the image.