Cleaning Lesson - The Basics: Understanding Layers

[shinwei]

Layers are perhaps the most powerful function ever contrived in graphics design software. Their concept is extremely simple, and also essential to anyone who ever wants to be able to do pretty much anything in Photoshop.

Here's my attempt to explain what layers are and do, with some links below to some other people's explanations just in case you still don't understand:

• A layer in Photoshop is "container" that contains graphical data.
• Using layers means that the file you are working on is not "flat". Instead, it consists of multiple images stored in layers stacked on top of each other.

Let's say I opened up Photoshop and I drew a circle. Now I want to give my circle eyes because I want to turn it into a smiley face. I have two options: 1) Just draw the damn eyes, or 2) Make a new layer for the eyes.

You should be familiar with option 1. Let me explain option two.

I'm now going to use an ANALOGY.

Have you ever seen 8.5 inch x 11 inch (standard paper size) pieces of plastic that are transparent? Also known as "laser transparencies" that I can print stuff on and then display onto a white screen by shining a lightbulb behind it? That's essentially what a layer is.

In Photoshop the layer at the very bottom (also known as the background layer) can be likened to a piece of paper. Every layer I create on top of that is a sheet of transparency.

So in real life, let's say I draw a circle on a piece of paper. Now I want to give it eyes, but I'm not gonna just draw them, I go to my local stationary store and buy some laser transparencies. I put the transparency on top of my paper where I drew the circle, and then I draw my eyes on top of that with a marker (markers can draw on plastic).

There are a couple of advantages to this:
1) I can move the piece of plastic transparency around freely without affecting the circle under it.
2) I can wipe and erase anything I draw on the plastic without having to worry about affecting the circle under it.

That's exactly how a layer works in Photoshop, only I don't have to go to the stationary store to place a transparency on top of my paper, I just hit the New Layer button at the bottom right of my screen. I also don't have to only use marker, I can use all the Photoshop tools I want on my layers.

Get it now?

Further Reading:
http://personal-computer-tutor.com/abc5/v41/linda41.htm
http://www.beckhamdigital.co.uk/onlinetuts/layers/layers.htm


If you have more questions, feel free to ask.

 

[La_Muerte]

cool, i knew this but u made it sound simple and i understand it better than i used to

 

[shinwei]

I figured it's the perfect starting point for our Lessons. If you don't understand Layers, then you pretty much can't do anything ^_^

 

[delete]

I have a question. What are the modes for? Normal, multiply, darken, etc. What does each one do? ^^

 

[shinwei]

Normal is normal.

Screen and Multiply are opposites of each other, and are the most useful non-normal modes.

Screen will make the layer only display the parts of the layer that are brighter than the layer(s) beneath it.

Multiply will make the layer only display the parts of the layer that are darker than the layer(s) beneath it.

Brighten and Darken do the same thing, but not as well because they're not as anti-aliased.

I don't really know what the other ones do.

 

[Fnuckale]

Darken just shows the parts darker than the parts below it as normal (so parts brighter than the parts above it in the darken layer will totally disappear).
Multiply basiclly covers the layer beneath while making it darker (parts brighter than the multiply layer will show, but will be darker).

I'm so bad at explaining stuff..

 

[Leen]

Thanks for the explanations. :knk
I really appreciate the explanations. I only use mutiply, soft light and normal. I never know the usage of luminosity, exclusion and so on. >.> There's even a mode called 'color'. What exactly does it do?

 

[delete]

Thanks for the explanation ^^

n00bish question:
Is it possible to merge just two, three layers, etc, but not all? If so, how?

 

[Fnuckale]

@delete just select the layers you want to merge (using control and left click) then right click em and choose merge layers ^__^

@Reen I will take a look and perhaps make a list of them :@

 

[shinwei]

@delete: Also when you select just a single layer, and hit CTRL-E, it will merge with the layer directly beneath it.

 

[fatetastarossa]

Thank you It's easy to understand ^ ^