DIYday Lesson 8: GIMP 101: Open, Save, Layers and Tools

This will be a first in the GIMP series. You’ve seen me write about it before and that is because this is one resource I cannot do without. I have tried Photoshop–a ridiculously expensive piece of you-know-what if I’ve ever seen one. They nickle and dime you for anything you want to add on or update, and it’s so convoluted I couldn’t figure out more than the most basic of things after a year of it sitting on my computer. With GIMP I was up and running in a week.

GIMP stands for GNU Image Manipulation Program (and GNU, in case you were interested stands for GNU is Not Unix… don’t ask…). It is available for Windows, Mac, and Linux operating systems. It is free and open source, which means you can use it without having to pay anything, and if you’re a programmer, you can also alter the program itself to do something different if you would like. A word of caution, it is a RAM-heavy application, which means if you have less than 1GB RAM you should not run it. Then again, if you have less than 1GB RAM what you need more than a program is a new computer.

Although GIMP performs most (if not all) of the same functions as Photoshop, it looks and works differently. If you’ve used Photoshop before and look at GIMP for the first time, don’t be scared! It really is fun and easy to use. Just take it one step at a time. If you’ve never used a program like this before and the words RAM-heavy freak you out, take a deep breath, it’s going to be okay. =) I’ll walk you through the basics and before you know it you’ll be a GIMPing pro!

For the purposes of these tutorials, all instructions will be for Windows operating systems because that is what I use. If you have a Mac or Linux computer, there are tutorials out there, so don’t be afraid to Google. This being a very basic intro class, it will be a most basic How-To for the simplest tools. I will have more for you next week.

So let’s get started!

Open

This is what GIMP looks like when you open it up. In addition you will have two other windows (toolboxes, see below). Do not close those. Take it from someone who’s done it. They’re a pain to get back.  To being, click on File –> New to open a blank canvas. You will get a pop-up asking for specifications. The default measurements in GIMP are in pixels. That is what most sites measure in also. If you’re not comfortable with that, you can change it to inches or centimeters. Enter the size you would like and click OK.

You can also open an image you have saved on your computer. Just click File –> Open and find the file you need in the browse window. Another cool trick is Open As Layers, which opens the image as a new layer in your current file, as opposed to a separate window. Don’t use this if you want to only use parts of the image. It creates an image-on-white layer, which means when you erase part of it, you get only white underneath and can’t see the bottom layers. To get it onto a transparency, open the image on its own, copy it, and then paste in your project on a new transparent layer.

HINT: When you paste something onto a new layer, GIMP allows you to manipulate it before it is “anchored” or attached to the layer. Until it is anchored, you will not be able to manipulate the other layers. When you anchor, the image automatically crops to the size of your canvas. This is not an issue, unless the image is larger and you later decide you like a different part of it more. To preserve the original size of the pasted image, click Layer –> To New Layer. This creates a new layer from your pasted image without cropping it.

Save

Saving in GIMP is a little tricky, but in a good way. By clicking File –> Save you save the project you are working on in separate layers, however many you have in .XCF format, only readable by GIMP. This is a cool new feature in the latest version. So helpful because it preserves everything in case you want to go back and change things. I can’t tell you how many times I accidentally saved something as .JPG and had to redo the entire graphic again from the start.

To save in a format you can post on a website or print, you need to Export or Export to. The most common image formats are .JPG, .PNG, and .GIF. Each is good for something different. For example, I use .JPG for covers because it is high resolution and all detail is preserved–it is optimized for printing which always requires the highest resolution image possible. But this format also creates a large file which is slow to load in a browser, so for website graphics I use .PNG. This compresses the file, makes it easier to load, and also preserves transparencies if you have them. But some of the details might not be precisely print quality perfect so if you want an image for printing, go with .JPG. The last format, .GIF, can be used for regular images. To be honest I am not quite sure what the difference is here. But I do know .GIF allows you to save animated images (ones that move or switch between one picture and the next).

HINT: The more you compress something, the less detail it has. Image resolution tells you how much detail is saved. In simple terms, if you zoom in on a picture, is it still sharp? How about if you zoom in more? Resolution can be measured in pixels per inch and the more you have the better the image will look, but the larger it will be. For print purposes, larger is better, because small images do not stretch well (they blur or pixelate). However, for websites, a large image can make your page slow to load. You don’t need super high resolution images on your site unless you are making an image portfolio. For things like buttons, banners, decorative touches, etc. it’s better to have smaller, more compressed images.

Layers

One window in one of the toolboxes is Layers. Layers make cool graphics possible. They let you add elements and integrate them together, move them around together or independently. When you create an animation like the one above, you essentially create a bunch of different layers that cycle through and “animate” your image.

As you can see here, you can have many layers. The checkered pattern indicates that layer is transparent. When you paste something onto it and erase a part, the layer beneath it will show through. The Background layer in this example is a white background layer, when I paste something onto it and erase a part, only white will show through regardless of how many layers I put beneath it.

Mode lets you set how the layer behaves with the others. I most often use Normal and Overlay (This superimposes the layer onto what’s under it, with interesting results). Opacity is how transparent you want the layer to be. 100% means all you see is the top layer. 0% means the top layer is invisible.

Speaking of invisible, see that eye symbol? If you click it it disappears and that layer becomes invisible so you can see what’s underneath. See the blank space between the eye and the mini layer? If you click it a chain image will appear. Click it on another layer and it will lock those layers together so when you move one, the other moves also. Great tool when you have the perfect grouping of texts in the wrong location. Move one and they all move. Easy!

HINT: Depending on what you paste onto a layer, it might not be the same size as your image. This is fine while  you’re working with the image, but to export it, it’s best to have all layers the same size. It trims unnecessary information and makes the file a little smaller. One trick is to click Edit –> Copy Visible and then create a new canvas with the same dimensions and paste there. That “flattens” the image (sticks all individual layers together) and makes it one size.

Tools

There are many. I use some, but not all. This is the third window you will work with. Select tools are awesome. You have five of them, the first row of icons and the first one in the second row. The cool thing about them is that when you select an area on one layer, unless you click elsewhere to deactivate the blinky dotted outline, the selection carries to every other layer. So let’s say I have a square on my background layer. I select it, then click on the topmost layer. The same area is still selected. But when I use Bucket fill to paint it blue, it’s on the top layer, and my square in the background is still the same.

Move tool (the four-directional arrow) does exactly that. Crop (the one that looks like a knife, 3rd row, 2nd icon from the left) will crop your entire canvas, so don’t use it if you just want to make one layer smaller. For that, use the eraser tool. Rotate, Perspective and Shear are great for manipulating different layers to get just the right look. The Text tool lets you add in text (which creates a new layer so don’t worry if you mess up). GIMP automatically searches your computer on startup and imports all the fonts you have on your computer. Can’t find the right one? You can always find more online.

Bucket fill is a fun one. You can fill in selections or whole sections with flat colors or with patterns. This is one thing that is worlds easier than Photoshop. You just select the bucket tool and then make sure you fill the selection with Pattern, rather than Foreground color. Click where you want to fill and voila! Easy as pie.  Brushes are a topic onto themselves, so they will be elaborated on later. The clone tool lets you copy parts of an image and paste not in chunks, but with a brush. This tool tends to be overused when people don’t know how to use the other tools and filters. I did it in Photoshop a lot. I haven’t done much in GIMP. Blur tool blurs with a brush (there is also a blur filter which applies to the entire layer and can add cool effects).  Smudge does exactly that and a Spot Healing brush does something really cool which I have no idea how to define. It’s like a clone stamp, but not. It integrates one part of the image into another seamlessly.

Wow, that was a lot for an intro. Take a breather.  It may seem impossible at first but, trust me, GIMP is addictively easy. You’re going to love it. If at any point in time you get confused about how a tool is used, don’t despair. The Help button takes you to an easy-to-read online manual where you can find more instructions. If there is a special effect you want to create, type it into Google. Odds are you will get tons of results for manuals and videos on how to create it.

One last hint: If you use images in your creations, always use high resolution images and always make the canvas larger than you think you will need. You can easily make a big thing smaller, but a small thing won’t stretch easily into a bigger frame.