Part 4: Layers and The Erase Tool

In this fourth part of our guide, the fun stuff continues with layers. We also discuss the erase tool as an exercise to show off our layer techniques.

In the previous part of our guide, we discussed a variety of features in Photoshop. This includes the filters, opacity, curves, and colour balance tools. So, we figured it was time we continue moving forward with another interesting tool: the erase tool. First, we cover layers so we are prepared to use the erase tool effectively.


Layers can be extremely useful. First, let’s open up a new project.

If you don’t have the layers tab open already, you need to click on the tab highlighted in this screen shot.

By default, you’ll only have one layer. This is the “Background” layer. If we are just messing around in the one layer, then this is fine. However, we want more freedom with these layers. So, the first thing we need to do is double-click on the layer.

When we do this, we are going to get a pop-up window asking us what we want to do with the layer. By default, we are turning it into “Layer 0”. For now, this is fine, so we’re going to click “OK”.

It doesn’t look like much has changed, but a lot has actually functionally changed. For one, the lock is missing meaning we can rearrange that layers order. We’ll be able to take full advantage of this later on in this part. First, let’s erase the white from the layer with the eraser tool.

I just used the eraser tool and increased the brush size by a lot to make this process quickly.

Next, I just use the paint brush tool to create a simply squiggly. Yes, I also increased the size of the brush while I was at it so you guys can see this much better.

Now, I create a new layer by clicking on the new layer button on the bottom right corner (highlighted in screen shot). You’ll notice that this puts a new layer over top of the previous layer (also highlighted).

With layer 1 selected, I’m going to change the paint brush colour to red and draw another squiggly. I changed the colour in the area I’ve highlighted above. The goal is to create a colour different from black so you can see what’s going on, so specifics won’t be that big of a deal.

You’ll likely look at this and think that it’s just two squiggles. Who cares? Well, try clicking on layer 1 and dragging it below layer 0.

You might notice a subtle difference, but you may not know exactly what has changed. Look closely at where the two colour squiggle lines intersect. You’ll see that black is now over top of the red. Before, red was over top of the black squiggles. By adjusting the layer order, you change what you see first. Already, we have pretty good control over our picture considering it’s just two random lines. Just remember that Photoshop reads the layers from top down on that list. The higher up on the list, the further forward that picture is.

Now, another cool feature Photoshop has is the ability to hide layers. If you click on an eye icon where the layers are, you’ll be able to turn that layer off. Let’s click the eyeball on layer 0.

When the eye disappears, everything on that layer hides. As you can see, all you can now see is the red squiggle. You can bring it back by clicking on the box where the eye used to be to bring it back.

One last thing about layers that we’ll cover here. If we have a lot of layers and we want to prevent edits of a specific layer, we can lock those layers.

To lock a layer, just select the layer you want to lock and click on the padlock icon (highlighted). To unlock it, just select the layer you want to unlock and click on the padlock icon again.

One last note: To rename the layer, just double click on the title and type in what you want to name that layer.

Pretty cool! You now have a basic understanding of layers!


You might be sitting there thinking, “Pff, why would I need a guide on erasing stuff? It’s just click on a button and click and drag, right?” Well, in Photoshop, it can be more complicated (and useful!) than you might think. Let’s say you have taken a picture of a coffee cup. It’s a good coffee cup, but it has a background. Let’s try erasing the background.

First, lets click on the erase tool (highlighted). Now, we are really clever and are able to figure out how to adjust the brush size (also highlighted). OK, let’s just get some erasing done!

OK, ouch. That didn’t work well at all. In fact, this picture is completely unworkable. In some parts, the table is still there. On other parts, I accidentally deleted part of the mug. In fact, I didn’t even start erasing the table inside the handle. Obviously, this isn’t going to work.

I could simply zoom in and erase very carefully, but that involves a tonne of work. Wouldn’t it be great to simply find a better way to accurately erase part of a picture and not all of it? Well, first, let’s convert the image to layer 0 for the purpose of editing just like what we did above.

Next, let’s create a new layer and move it to the bottom. All this looks quite familiar so far, right? Good.

Now, we are going to use the Magic Want Tool and select an area we want to erase. You’ll notice that it has highlighted a section of the picture outside of the coffee cup. Not everything we want highlighted is selected, but the critical areas will work for us no problem.

Next, we are going to click on the erase tool, using a really big brush size, and just delete what is highlighted. It won’t be perfect, but boy does this save time on creating an otherwise accurate cut. Next, lets select another area to erase by clicking on the wand tool and clicking on another area.

So, as we can see, the selection is by no means perfect. It highlighted a part of our coffee cup in the process. The reason it did this is because the shadow made the background look similar to our wand tool. Obviously, our selection is no good. So, what do we do in instances like that? Simple, just adjust the tolerance:

Now, the lower the number, the more finicky the wand tool will be with pixels. This can be general trial and error. Too high of a number and you’ll start selecting parts of the coffee cup. Too low of a number and you’ll barely highlight any of the table. For me, in this instance, I want in increments of 5 units until it highlighted too little of the table. I then figured out from there what will highlight the cup and what won’t. The number that highlights the most table without highlighting parts of the cup will be the magic number I use for selecting in this case. In this case, my magic number wound up being 16. So, I just use the erase tool after and continue erasing.

After some additional selections, zooming in and out, adjusting the paint size for the erase tool a couple of times, and even doing some unselected erasing (with the texture of the table, it will leave specs everywhere which can be cleaned up easily enough as long as it’s not too close to the cup). Eventually, we’ll get this nice clean looking cup. By no means is it perfect. One of my selections chewed into the cup a little. While I could go back and more carefully adjust my tolerance levels with the magic want, this is actually very sufficient for what I’m going to do next. That is…

… send it into outer space. The perfectly logical next step! All I did was Open up the space image in a new tab, converted that to layer 0, then use the select tool (dotted box, second from the top on the left hand side) in the mug image to highlight it. After that, I copied it over into the second tab. From there, I selected the layer with the mug and pasted the mug. After that, I used edit, then free transform. Using the shift button on the keyboard, I shrunk it down to fit the image (holding shift allows me to scale down without affecting aspect ratio). After that, I highlighted a corner just a little bit out of the highlight box and clicked and dragged to rotate the mug. You might see imperfections if you look really closely, but the effect works.

That’s it! You now know how to effectively use the erase tool and layers. You even got a lesson on how to use the magic wand tool. Not bad at all!

< Filters, Opacity, Curves, and Colour Balance | Index | Clone Tool and Liquefy Tool >

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.