Tutorial 03: Understanding layers

Understanding layers

You have to work with layers when making an OOB therefore it is crucial that you understand how layers work. Without getting too technical I will try to explain the basics of raster and vector layers. There are more types but for out purposes it will be sufficient to just understand these two. You are advised to read the information in your editing software about layers.

1.     Layers are like separate sheets that you combine to create a final composition. All layers stacked on top of each other with some as transparent sheets and others with cut out parts to make up the final creation with the parts that are visible from each of the layers when all are put together. By arranging the layers differently in this stack or taking out some and adding others one can obtain a totally different final image.

2.    One starts off with a background layer when opening a jpeg image in the software programme. Many tools and editing actions do NOT work on background layers therefore we usually have to convert the background layer to a raster layer. The background is the bottom layer of an image.( I know it is confusing but for lack of terminology I also sometimes refer to the layer outside the main part of a photo as a “background” in the context of the background of a photograph.)

3.    Raster layers only contains raster data. Raster data is composed of individual elements, called pixels, arranged in a grid. Each pixel has a specific location and colour. Photographic images are composed of raster data. If you magnify raster data, you can see the individual pixels as squares of colours.

Vector layers are layers with only vector objects (lines and shapes), vector text, or vector groups. Vector objects and text are composed of geometric characteristics — lines, curves, and their locations. When you edit vector objects and text, you edit these lines and curves, rather than the individual pixels. Vector graphics and vector text maintain their clarity and detail at any size or print resolution (and does not show up as squares of colour).

On the left side is an image with different layers and on the right hand side an example of how the layers palette will show up the various layers. You will notice (see red arrow top right) that the top layer is lit up and at the top of the layers palette it says “blue flower…” indicating that this is the “active” layer. One has to always make sure that you work on the correct activate layer by clicking on that layer before using any tools

From bottom to top the layers for this image are as follows:

1. A transparent raster layer created when the new file was created as a transparent image. Since I did not open this file from a photo it was created as a new raster layer and therefore do not show the bottom layer as ”background layer”

2. A raster layer called “Black Background” to denote its position in the layer stack (I should rather have called it “Bottom layer” to avoid confusionJ)

3.A red vector line drawn with the rectangle shape tool. The stroke in red with no fill to make the background show through both inside and outside the rectangular red shape

4.A rectangle shape selected with the rectangle SELECTION tool (The shape along the lines of the inner yellow line) and filled with a leaf pattern

5.   An inner yellow vector line with stroke in yellow and no fill to also make the inside and outside transparent

6.A flower pattern in solid colour but with outer part transparent. The petals of the flower will appear as if they are outside the yellow border because the yellow line is UNDER the flower layer.