Layers
There are three graphics layers in every Canvastic document. The
are called the background, paint and object layer. They appear in
that order from farthest away to closest. The presence of these
layers creates more complex possibilities in the publishing and
presentation of information with Canvastic. Any layer can be hidden
or shown by using the commands under the View menu. Read the following
section for an explanation of each layer.
Background Layer
The background layer is the one farthest away from the user. The
background layer by default is white. You do not need to do anything
with it if you just desire a white background. You can add a color
or picture to the background. Use the Background… command
from the Settings menu.
The background layer cannot be altered by any of the paint or
object tools. . It can be covered, however, by paint and objects
on layers in front of it.
You can think of the background layer as the color or design of
the paper or canvas that you are creating upon. Teachers may use
the background layer to place directions or graphic organizers to
aid students. Some graphics are included in the backgrounds folder
for this purpose. Most common graphical file formats and Canvastic
documents can be used as background pictures.
Paint Layer
The paint layer is the next-closest layer to the front. It is closer
to the user than the background. The paint layer hides the background
layer as you use the paint tools like the brush to create shapes
and marks. The paint tools color individual dots called pixels.
They are sometimes called bitmapped graphics. For example, when
you paint a red stroke across a green area the red replaces the
green. Painted graphics can be erased bit by bit with the Eraser
tool. These are the tools used when actually creating a hand drawn
picture of a house or animal or scene. Most primary students will
use only the bitmapped or paint tools. The paint tools are normally
used when drawing pictures. The Paint tools only affect the Paint
layer but as previously mentioned they cover up the background layer.
See the Paint Tools section for more information about using the
Paint layer.
The paint tools: 
Object Layer
The object layer is the closest layer to the user. The object layer
contains shapes and lines that exist as separate objects, which
do not erase what is underneath. They can, however, hide what is
beneath them. Because they exist as separate objects, they can be
moved around and positioned independently or in groups making it
possible to layout a page for printing in an exact way. Object graphics
can be deleted with the Delete or Backspace key but not erased pixel-by-pixel.
Object graphics can easily have different choices applied them such
as color, thickness, and size because they are not painted on the
screen. They are actually the math formulas that describe the shape
and colors for display on the screen. We often refer to what we
create as drawings. We say we drew a picture. However, in computer
graphics we paint the picture and create draw objects. Drawn objects
are sometimes called vector graphics. Objects are often used to
aid in "laying out" a page for publishing. In publishing
layouts, each object can be arranged on the page in the exact location
desired. See the Object Tools section for
more information on using the Object layer.
The object tools: 
Stack Order
Each individual object that is created exists on its own invisible
layers within the Object layer. This is called the stack order.
Any object's place in the stack order can be changed via the Arrange
menu. See the Arrange Menusection for more information on adjusting
the stack order.
In this illustration, the yellow object has been moved one step
forward or up in the stack order.
Moving Graphics
from the Paint Layer to the Object Layer or Vice Versa
You can move a paint selection to the object layer or an object
to the paint layer by following these directions. The key is in
selecting the right kind of tool right before the "Paste"
step.
Paint to Object
- Select the area you want to change with the Selection Rectangle
or Lasso.
- Choose Cut from the Edit menu.
- Select one of the Object tools.
- Choose Paste from the Edit menu. The graphic will be pasted
into the canvas as an object since an object tool was selected.
Object to Paint
- Select the area you want to change with the Pointer.
- Choose Cut from the Edit menu.
- Select one of the Paint tools.
- Choose Paste from the Edit menu. . The graphic will be pasted
into the canvas as paint since a paint tool was selected.
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