How To Use Basic Functions In GIMP For Beginners

If you don't currently have GIMP installed, you can download it here.

Upon opening GIMP, you should be greeted with the main GIMP window, the toolbox and also the layers dialogue window. As we're just starting out, these three are all you'll be needing.

Sometimes these dialogue boxes might go missing. Often you'll close them without thinking and they can be hard to get back. Fortunately, there's two simple ways to get back missing dialogue boxes:

The keyboard shortcut to bring up the toolbox is CTRL+B. This is handy to know purely because the toolbox is the most likely dialogue box to accidentally be closed. The layer dialogue is similarly vulnerable to closing accidents and can be re-opened using CTRL+L.

It's not practical to learn all of these shortcuts and there's an alternate method of getting the dialogues back using the menu bar across the top of GIMP. To do this, go to Windows > Dockable Dialogues and choose whichever dialogue box you wish to use.

As the name suggests, this is where all of the tools are kept and where you'll be spending most of your time. There's quite a few tools to get used to and each of them have their own settings once you've selected the tool, but I'll provide a short explanation for what each is and when you might want to use it.

The best way to get to know these is to simply play around with the settings and try them out. It's surprising what you can create just by messing around!

There is a lot of tools at your disposal so the following list is quite long - it might be worth a quick read, but will probably be most useful to refer to if you're unsure of what something does.

 Rectangle Select Tool (R) - This is simply used to select a rectangular area of an image.    Selections in GIMP allow you to only work on that part of an image you selected.

Ellipse Select Tool (E) - Again, this is for selecting regions to work with, but instead of it being rectangular, it's elliptical.

Free Select Tool (F) - This allows you to hand-draw the selection you wish to work on. It's good for defining precise selections.

Fuzzy Select Tool (U) - Selects an area around where you clicked based on the colour of the pixel you clicked on. Good for selecting a large area of a certain (or very similar) colours that are directly next to each other.

Select By Colour (Shift + O) - This is like the previous, but it selects all the pixels that are that colour no matter what their location. It's useful for eliminating a certain colour.

Scissors Select Tool (I) - Similar to the Free Select Tool, however it intelligently snaps the selection lines you're drawing to the edge of what you're attempting to select.

Foreground Select Tool - Used to select a region to be marked as the foreground.

Paths Tool (B) - Used like the Free Select Tool, though you're able to create much smoother selections which are good if you're looking to use the selection for say a fill or              cutting out a smooth area.

Colour Picker Tool (O) - Used to select the colour that you've clicked on. Very useful for shading and getting colours close to those around it.

Zoom Tool (Z) - I'm sure you're aware of what a zoom tool would be useful for.

Measure Tool (Shift + M) - Allows you to measure distances and angles, good for very precise work.

Move Tool (M) - Allows you to move selections or entire layers.

Alignment Tool (Q) - Allows you to align objects and layers easier than by hand.

Crop Tool (Shift + C) - Used to remove parts of the picture you don't want.

Rotate Tool (Shift + R) - Used to rotate selections or entire layers.

Scale Tool (Shift + T) - Used to scale entire layers or selections.

Shear Tool (Shift + S) - Allows you to "slant" an image.

Perspective Tool (Shift + P) - Enables you to change the perspective of a selection or layer.

Flip Tool (Shift + F) - Allows you to flip an entire layer or selection vertically or horizontally.

Cage Tool (Shift + G) - More precise version of the Perspective Tool. Gives you more control over how the perspective changes. It's somewhat tough to use. We're not the best of friends.

Text Tool (T) - Adds a new layer and allows you to add text.

Bucket Fill Tool (Shift + B) - Allows you to fill in a selection or layer with a certain colour or pattern.

Blend Tool (L) - Like the Bucket Tool, but allows you to fill selections and layers with gradients.

Pencil Tool (N) - A brush with a hard edge meaning that it uses solid colours and no semi-transparent pixels.

Paintbrush Tool (P) - Allows you to create smooth strokes, but isn't a hard edge meaning that it can get troublesome if you then wish to select the line.

Eraser Tool (Shift + E) - Erases whatever's in its path leaving either the background or transparency.

Airbrush Tool (A) - Much like the Spray Tool in MS Paint, it allows you to draw as if you were using a can of paint.

Ink Tool (K) - Allows you to draw in a style akin to calligraphy.

Clone Tool (C) - Allows you to select an area and then clone the selection elsewhere. Very useful tool for anything relating to adding something in to a picture as it allows you to blend the edges easier.

Healing Tool (H) - Removes blemishes from photos. This is what you'll want to use if you'd want to perhaps enhance a picture yourself - not that you need it, I'm sure.

Perspective Clone Tool - Used like the Clone Tool, but this allows you to clone to a perspective meaning that if your image is at a perspective, the clone will conform to that perspective rather than simply duplicating.

Blur/Sharpen Tool (Shift + U) - Allows you to blur or sharpen an image with the use of a brush rather than applying it to the entire layer.

Smudge Tool (S) - Used to blend two parts of an image together. Use it sparingly however as the more you use it, the more noticeable it becomes.

Dodge/Burn Tool (Shift + D) - Allows you to create either lighten or darken a part of an image.

Phew.

A big part of upgrading from software such as MS Paint to a more in-depth program like GIMP are layers. They can be tricky to understand and get to know when to use, but once you know what they are, you'll wonder how you made do without them.

The way I understood layers was to think of them as panes of glass. Each image can and most likely is comprised of several different layers stacked in a certain order.

Say we had an image with two layers. The bottom layer contains the GIMP mascot and the on the top layer, someone happens to have scribbled over it.

Normally this would be bad news - the picture would be ruined if a previous version wasn't saved. However, since we're using layers, we can simply remove the layer on which the scribble was drawn.

Hiding a layer from view is done by clicking the eye to the left of the layer.  

This removes it from view, but doesn't actually remove it from the image. To do this, we must right-click the layer and press Delete Layer.

Now, that's not exactly what layers are used for, it's just a good way of demonstrating how they work. Using the previous analogy, deleting a layer is like removing the pane of glass.

The list is drawn from the bottom up. This means that the very bottom layer is drawn first, then the layer above that and so on. Anything on a higher layer will be seen on top of the layers below that.

As you can see, the red lines appear above everything, the GIMP mascot appears above the blue lines, but below the red lines and the blue lines are behind everything. It follows the order in the Layers dialogue box.

So, now you've got the basic idea of what layers are and how they work, you're probably wanting to know what they're used for.

There's no single answer to this as they're used for a multitude of reasons. Personally, I use layers the most when I'm either adding effects to certain parts of an image or adding something else extra to an image. 

Ideally, having a background layer and leaving it alone is a good idea as this leaves you free to modify anything in the foreground without worrying about damaging the background.

 New layers are created by clicking the icon that looks like a page in the bottom left of the Layers dialogue box. Alternatively, you can use CTRL+SHIFT+N.

 Layer ordering isn't fixed either - you can move them around freely. Below, the lines are switched around. The layer names are the same, but this is to show that layers are able to be manipulated easily.

This would've been extremely difficult without the use of layers. This is the most basic of situations in which layers are useful.

You might notice that one layer has a grey background (blue if the window is focused on). This is the layer that's currently active meaning that if I were to modify the image in any way, that would be the layer the change would be applied to.

Filters are special effects that can be applied to entire layers or just small selections. They're used for heavily modifying certain properties of an image. You can browse the list by clicking Filters across the top of GIMP.

There are far too many filters to go into detail on each, as with the tools, it's fun to play around and see what each of them do. They're grouped well so it's easy to get an idea as to what the filter will do.

Above are examples of a ripple filter and an emboss filter. You can see just how drastically one filter can affect an image. It's important not to overdo the filters, but you can get some impressive looking images purely from adding several filters together.

Under the Colors menu, you'll find what are essentially filters that change the overall colour of the picture. This is a decent method of making your skies bluer and your grass greener. Again, there's far too many to list individually, but are enjoyable to play with.

One of the most common things people use GIMP for is to create transparencies. Now you're aware of what layers are, understanding transparencies should be easy.

First things first, you're going to need your image. I'll be using the following image, feel free to create a transparency with it too or use your own.

Admittedly it's garish, but with good reason. As you can imagine, we're going to need to remove the background and removing it while there's plenty of different colours there can be problematic. It's certainly still doable, but you'd have to use a different selection tool for the job.

If you're having issues, it's best to fill the background you want to get rid of in a colour that's not going to get mixed up with the actual image (hence the hot pink).

First, what we're going to need to do is add an alpha channel to the layer. This is done by right-clicking the layer in the dialogue box and selecting Add Alpha Channel.

 An alpha channel is used to mask the background of your image and set all the pixels to display as transparent rather than a RGB value.

Now, select the Fuzzy Select Tool and click the pink. This will select any pink pixels (or any colour close to pink) that are next to each other.

Now, press delete on your keyboard and the pink will disappear leaving you with a checkerboard. The checkerboard marks what part of your image is transparent.

All that's left to do is export your image. You have to export your image rather than just save it as simply saving it will only save the GIMP file. To export, go to File > Export or CTRL+SHIFT+E.

Make sure to save your picture with a filetype that supports transparency - .png is a good choice!

If you'd like a guide on anything, please ask below!