Every time something new is drawn onto the current icon, for example a filled box, it is
possible to decide if the box is to be totally opaque or if the existing colors underneath
the box will show through. In the options box on the right of the toolbar is the
transparency level. A value of 1.0 means that the new pixels will be totally opaque and a
value less than one indicates transparency will be used. The lower the value set then the higher
the transparency. The lowest possible value is 0.1 and this can be reached in increments
of 0.1.The ability to create transparency is another feature of IconPainter that allow the creation of really beautiful and unique icons. The image of the series of boxes at the top of this page illustrates the kind of effect that can be achieved using a combination of transparency and gradient shading. As the boxes get nearer to the viewer they have been made more transparent.
Images saved to the Microsoft ICO format follow similar rules to GIF. The background color is not saved in ICO resource files and it's not possible to know what kind of background a ICO image will appear over (that also applies o the CUR format).
