The Paint Bucket, also known as the fill tool, is used to fill a canvas, a layer, or a selected area with colour by clicking in it. It will replace all pixels that are the same or close to the pixels that you click on, based on a tolerance that you can specify.

 

 

The paint bucket is grouped with the gradient tool, but it is used to apply an even coat of colour, where the gradient tool is used to apply a geometrically changing colour effect, (a gradient).

 

To use the paint bucket, you must first have an area in mind that you want to fill. As an example, we will use the eagle image shown below.

 

 

The region that we want to fill with colour is the green background. This should be easy because the pixel values (colour) of the background are quite uniform.

 

To fill the background with a different colour (say orange) we must first specify it as the foreground colour. You can do this by selecting the eyedropper tool in the toolbox and then clicking on the orange part of the colour band running along the bottom of the Colour palette.

 

 

 

Alternatively, you can click with the eyedropper on a colour square in the swatches palette.

 

 

 

When you click on the colour bar or on the swatches palette, the foreground colour square in the toolbox will automatically assume the colour that you click on. Once you have chosen your foreground colour, select the paint bucket tool from the toolbox by clicking on it.

 

When you select the paint bucket tool, you will see the paint bucket options in the options bar.

 

 

In the drop list labelled Fill, you can choose from Foreground, meaning the foreground colour, or Pattern, meaning one of the patterns from the pattern drop list that is the next option to the right. Since we want to fill the green area of the eagle image with colour, not a pattern, we will leave this setting as Foreground.

 

Next to the Pattern drop list, you will see the Mode drop list. From this list, you can choose how the fill effect will be blended with the image. We will leave this setting as normal for the purposes of this example.

 

Next, you can use the opacity slider switch to set a transparency for the fill effect. Again, for the purposes of this example, we want the fill colour to be 100 percent opaque.

 

In the Tolerance field, you can adjust how close the pixel values have to be to be filled from the paint bucket. A high value in the tolerance field will allow more colours to be filled without distinction. A low value will cause the fill to be confined to areas with pixel values that are very close to the pixels that you initially click on. A value of 32 should be plenty for the purposes of this example

 

You can place a checkmark in the anti aliasing checkbox, to help smooth the edges or curves of your fill effect. If the contiguous check box is checked, only pixels that are adjacent (share a side) will be filled. If it is unchecked, any pixels that are within the specified tolerances will be filled.

 

To fill the Eagle background, click with the paint bucket tool on any part of the green background in the image.

 

 

Notice that the orange colour in the image is the same as the colour in the foreground colour square in the toolbox.

 

You can also make a selection with any of the selection tools, and click inside it with the paint bucket tool to fill only the selected region.

 

 

Here, the rectangular marquee was used to make a simple selection. The selection was then filled with the paint bucket tool. (Notice how the tolerance setting keeps the fill from covering the white and yellow colours of the eagles head and beak.)

 

Immediately after you fill with the paint bucket, you can choose Edit ->Fade Paint Bucket from the menu bar to display a slider that will adjust the opacity of the fill effect.

 

Note: If you set the blend mode of the paint bucket to clear, it will delete colour from a layer instead of adding it. (If the layer is locked this will not work.)