Life Behind A Lens

This is the second part to my other layers guide and is designed to give an overview of manipulating layers in GIMP.

In order to get the most from this guide, it’s worthwhile downloading this layers.xcf image from my website as it the image I’ve used to show the effects.
Once you have downloaded and opened the image in GIMP, you should see something like this:

The image contains 5, easy to spot, layers. Background (which is black) and then 4 layers with coloured rectangles in. Red, Blue, Yellow & Green. I’ve named each of these layers to their corresponding colour, to keep it easy to see what’s happening.

Now it’s time to play with them! :))

I’ve split this guide down into individual tasks and, while you can follow it through from start to finish, it’s not neccessary. If there’s a part that you already know, just skip it and move on. :))

1. Moving Layers Up & Down
In this part, I’ve decided that I want to reverse the order of the coloured layers so that instead of them being ordered Green->Yellow->Blue->Red they end up being Red->Blue->Yellow->Green

• Click on the Red Layer so that it’s highlighted.
• At the bottom of the layers window, click on the up arrow (as mentioned in Part 1 of this guide) until it is placed on top of all the other layers.
• The Red Layer Should now be hiding parts of all the other layers.
• Now, click on and select the Blue Layer.
• Click the up arrow twice, so that it ends up between the Red Layer & Green Layer.
• Select the Yellow Layer and click on the up arrow once, so that it finishes between the Blue Layer & the Green Layer
• If all has gone to plan, your image should look like this;

Now, we need to put them back again to their original order. (From top to bottom) Green->Yellow->Blue->Red.

2. Playing With Opacity & Modes
In this part, we’re going to look at what happens when we play with the opacity settings of a layer. So, first of all, bring the Background Layer to the top, as we did in section 1 of this guide, so that our image looks like this:

• Go to the Opacity Slider towards the top of the Layers Window and move it from 100%, down until you get to around 50%. Anywhere between 45 and 55% will do for this.
• What we’ve done is to make our Background Layer half see through. In this case, the effect has been to darken the colours of the four rectangles in our image.

Note: Incidentally, we have just carried out the most basic method of applying a texture to an image. Which is to place a layer over the top of our image and then adjust the opacity to taste. Well done you! :))

• Now onto the modes. If you keep your Background Layer selected and open up the modes dialogue box you’ll see that there are a range of different things that you can do. Because we are using solid colours, the effects of some will look very similar but we can play with them and see what happens.
• Spend a little while now, changing the modes of the Background Layer and seeing what the different settings do to the colours underneath. If you fancy being clever, try adjusting the opacity and modes of the Green, Yellow, Blue & Red Layers as well.
• When you’re done playing, return all the modes to normal, set all of the opacity levels to 100% and place the Background Layer back to the bottom of the pile of layers.

Note: You may have noticed that when you moved the Background Layer to the top of the pile and reduced the opacity, that a series of grey squares appeared anywhere that there wasn’t a coloured rectangle. This area would appear transparent in a finished PNG (useful for t-shirt designs) or GIF image. It will appear as white in a JPG file.

3. Duplicating & Deleting a layer
After playing with our layer modes and opacity we should now have returned our image to it’s original state, as it was downloaded. If you’ve experimented so much that you can’t do that, simply close and re-open the *layers.xcf (provided you haven’t saved it, of course lol)

• Now we’re going to duplicate the Background Layer, move it to the top of the pile of layers, play with it’s opacity and then delete it again.
• Select the Background Layer
• Go to the 4th icon in at the bottom of the layers window and click that. (That’s the Duplicate Layer icon)
• You should now have another layer, called Background Copy. Like this;

• Select the Background Copy Layer and move it to the top of the image as in section 1.
• Adjust the Opacity of the Background Copy Layer to about 50% again and you should now have an image, similar to the one in Section 2, but with the whole image in solid colour. Like this;

• Now, we’ve decided that we don’t want that Background Copy Layer after all. Select it and then click on the right hand icon at the bottom of the layers window.
• Our Background Copy Layer is now gone.

Hope that some of you find this information useful. The next step with what you’ve read here is to experiment with some of your own images that have more variation than just 4 solid colours to it. Something that might be worth looking at as a next step from here is using layers to produce a Selective Colour effect to an image. A tutorial for which can be found on this blog. That tutorial also includes using a layer mask to generate an effect.

Have fun with your layers!