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Using Gimp’s Rectangle Select Tool: Some Usage Examples of One of Gimp’s Selection Tools

The settings available when using the Rectangle Select Tool allow Graphic Designers to use the tool in a variety of ways to achieve different outcomes.

Produce a Colored Square           

The most simple use of the Rectangle Select Tool is to produce a solid rectangle or square.

To produce a rectangle, the user should select the tool and then click and hold the left mouse button on the canvas at the point where one corner of the rectangle is to be positioned . By then dragging the mouse, a rectangle is displayed as the mouse moves and when the rectangle is as required, the left mouse button should be released.

The outline now changes to moving dashes and by clicking on the Edit menu and selecting ‘Fill with FG Color’, users can produce a coloured rectangle. If a colored rectangle isn’t visible, the user should check that the foreground color is different to the canvas color. To remove the dashed outline, the user should click outside of the rectangle and the dashed line will disappear.

It should be noted that the dashed line will not appear in the finished image – it is only visible in Gimp to show that pixels are currently selected.

To produce a square, before drawing the rectangle the user should click on the ‘Fixed’ checkbox in the tool options tab, select ‘Aspect Ratio’ from the drop down menu and then type ‘1:1’ into the field below. When the Rectangle Select Tool is now dragged across the canvas, it will produce a square that can be any size that the user chooses.

Produce a Simple ‘L’ Shape

By default, the Rectangle Select Tool in Gimp is opened in ‘Replace the current selection’ mode, however using some of the other modes allows more complex shapes to be produced. The mode options are found in the first row of options in the tool options tab. There are two quick and easy ways to produce an ‘L’ shape.

The first way is to use the ‘Add to the current selection’ mode and to draw two intersecting rectangles to form a capital letter ‘L’ and then fill it with the foreground color. The difficulty with this method is ensuring that the two rectangles join neatly without any small bits jutting out and spoiling the perfect shape of the ‘L’. To remove the dashed outline, the tool must be in ‘Replace the current selection’ mode and then the user can just click anywhere outside of the ‘L’ shape.

The other method is to draw a rectangle outline and then change to the ‘Subtract from current selection’ mode. The user can then draw a smaller rectangle over the current selection, which covers the negative space of the letter ‘L’. Clicking outside of the dashed line will remove the outline of the second rectangle and should leave the user with an ‘L’ shape which can be filled with the foreground color.

To remove the dashed line, the tool again needs to be returned to the ‘Replace the current selection’ mode before the user clicks outside of the ‘L’ shape.

Crop an Image to Exact Size or Proportions

The Rectangle Select Tool can also be used to crop an image to a predetermined size using some of the other settings. Traditionally photographs have been in 3:2 proportions and it is easy to crop an image to these proportions.

Firstly the user should open a suitable image. They then click the ‘Fixed’ checkbox in the settings palette and select Aspect Ratio from the dropdown menu. In the field below they need to enter ‘3:2’ and select portrait or landscape mode using the two buttons to the right. When the Rectangle Select Tool is used now, it will only produce a rectangle with the fixed proportions of 3:2.

If the final image needs to be a fixed size also, pixel dimensions can be entered into the size fields. When using Aspect Ratio with a set proportion, only one size needs to be entered and the other dimension will change accordingly.

After drawing their rectangle selection, the user can click on the rectangle selection and use the mouse to drag it around the image until it frames the image as desired. The user then needs to click on the Image menu and select ‘Crop to Selection’ to produce an image of the exact proportions and, if selected, the correct size.


These are just a few uses of the Rectangle Select Tool in Gimp, but by experimenting with the various different options available, Graphic Designers may find many more interesting ways to use the tool in their designs


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