Inkscape Pop-Art Tutorial

Before we begin, an apology for the awful image quality in places. I've converted this from a Word Document and it seems to knacker them.

Inkscape is a brilliant, free vector drawing package available from http://www.inkscape.org/

This tutorial will attempt to show you how to create a pop-art style portrait from a photograph, similar to this one.

Inkscape Basics

When you first start Inkscape, it will present you with a blank, portrait format page.

To begin with it is useful to know how to manipulate your view with the mouse. Best control is achieved using a scroll mouse with a clickable wheel (middle button).

• To pan up and down, roll the wheel forwards and backwards.
• To pan left and right, hold down the <Shift> key and roll the wheel forwards and backwards.
• To drag the page, hold down the middle button (wheel) and drag.
• To zoom in and out, hold down the <Ctrl> key and roll the wheel forwards and backwards.

Page Format

The first thing you may want to do is set the size of the “page”. Although you can draw wherever you like in Inkscape, the Page determines the area that will be rendered if you choose to save your picture in a raster format.

Select File->Document Properties from the menu and you will be presented with the following dialog.

There are many options here, but for now we simply want to set the size and shape of the picture. I’m going to do a picture suitable for using as wallpaper so I’m going to create a 1024x768 page.

I simply enter the width and height I require in the appropriate boxes and the page outline in the main window is instantly resized.

One shortcut that is useful: pressing the <5> key will zoom the view to fit the page in the window.

Importing the Source Photograph

Select File->Import from the menu.

The file dialog is a little different to the normal windows one, but the trickiest bit is knowing that the little arrow top-left () moves back up the folder tree.

When you click the Open button the picture will be imported.

The great thing about the style of picture we’re creating is that you don’t need a particularly large or good quality photograph to work from.

You can left-click on the picture and drag it into position. Use the double-headed arrows around the edge to resize it: left-click on an arrow and drag the picture to the size you want. If you hold down the <Ctrl> key while dragging then the picture will stay in proportion.

Make the picture fill the page.

About Layers

Inkscape allows you to work on layers. These are effectively sheets of transparent paper on which you can draw, allowing you to place objects in front of and behind each other. When you start Inkscape you will be working on Layer 1; this is the layer we imported the picture onto.

The functions for working with layers are in the Layer menu and you can quickly switch between, lock and hide layers using pull-down menu on the bottom of the window frame.

There is also a very useful Layers dialog which can be opened using Layer->Layers... menu or <Ctrl+Shift+L>.

We are going to rename Layer 1, lock it and create a new layer to start working on.

Select Layer->Rename Layer.

To lock or unlock a layer, click the little padlock icon in the window frame

The name of the layer will be put in square brackets to show that it is locked.

To create a new layer, select Layer->Add layer from the menu.

Enter a name for the layer. You can define whether the layer will be above or below the current layer (the one shown in the window frame). You can also create sub-layers, but we don’t need to worry about that right now.

Click the Add button and the layer will be created and automatically made current. If we draw anything now, this is the layer that it will be created on.

Drawing

There are a number of different tools for drawing with; for creating rectangles, ellipses and polygons; but for this exercise we will be using the Bezier curve tool (left). Bezier curves are created by placing control points (nodes) that the line passes through. Each node can be either a vertex or a smooth transition and may also have a couple of additional control points that define the curve “tension”.

The above curve was created by clicking one end point, clicking and dragging to define the centre point and curvature, then double-clicking the other end point. Double-clicking or clicking on the start point ends the line.

Once a curve has been created you can use the node edit tool () to change it. When you click on a node, its control points (if any) will be shown. You can drag nodes and control points to alter the curve.

When editing nodes, a toolbar is available which allows you to change the characteristics of the selected node: whether it is a corner or smooth and whether it is symmetric. Corners are represented as diamonds, smooth transitions as squares.

It is worth practicing with a simple three point curve to get a feel for how the line behaves. This will help you when trying to trace outlines.

Stroke and Fill Style

A drawing object’s style is defined using the Fill and Stroke dialog which is shown by clicking the icon below.

The dialog consists of three tabs for Fill, Stroke paint and Stroke style.

The Fill and Stroke paint tabs let you set the colour of each. You can use a flat colour or a linear or radial gradient. In this tutorial we will only be using flat colours; however you can achieve great effects using gradients, and blur and opacity (planned for inclusion in a future tutorial).

The Stroke style defines the line thickness and style and also lets you put various start, mid-point and end markers on. The following diagram shows the previous line with various styles applied.

Tracing

We are going to start tracing the photograph. As new layers are generally created at the top of the stack, we will start by tracing something at the back of the picture: in this case the shoulders.

Using the Bezier tool, create a four point polygon which defines the outline of the shoulders. Click on the starting point at any time to create a closed curve.

It’s perfectly acceptable for the shape to go outside the bounds of the page as this will not be seen when we render a raster image.

Next we apply stroke and fill styles. I have used a 4 pixel stroke width and a cream-ish fill.

Now, here’s a trick that is useful while working to perfect a tracing. We can turn down the opacity of an object using the slider at the bottom of the Fill and Stroke dialog, allowing us to see the picture through it.

That’s all we’re putting on this layer so we need to create a new one. Select Layer->Add Layer to add a new layer above the current one. We’re going to put the neck on this one.

Just to make things easier to see, I'm going to make the "shoulders" layer invisible. I'm going to use the Layers dialog by selecting Layer->Layers... from the menu, then clicking the "eye" icon next to the "shoulders" layer.

Remember to click on the new "neck" layer to make sure we are going to be working on that layer.

Again, we draw a simple outline, tracing the neck. The face will go over the top so we don’t really need to worry about the top edge.

For the cartoon effect I’ve used a 4 pixel stroke and a flesh coloured fill. Because the ears go behind the face I’m also going to put those on this layer.

Here we see the new layer with the opacity turned down in the first picture, and all layers so far at full opacity in the second. It looks rubbish at the minute but it will get better.

Next is the face. Again, I’ll switch off the layers created so far and create a new layer, then create a simple outline of the face.

The hair is going to define a lot of the outline, so we only really need to worry about the contours around the chin and across the ear.

To make sure we get the face fill colour the same as the neck, we can use the object selection tool () to pick the neck profile then copy the RGBA field from the Fill and Stroke dialog. We then click on the face profile, select the RGBA field in the Fill and Stroke dialog, and paste the value in.

Of course, I had to unhide the “neck” layer to do this. Here’s what we’ve got so far…

The next new layer is the hair. Same as before…hide all the layers, create a new one and use the Bezier tool to trace the outline.

Now, the hair is where we really start tweaking the outline. Once we’ve traced the basic profile, switch on all the other layers (you might want to lock them) and use the node edit tool () to make sure certain intersections match up properly; for example, where the hair meets the collar. But there are also areas (under the arm) that will be covered and don’t need such attention.

The hair is also the only place where we’re going to add some highlights, so after creating the full outline, we create a few more profiles using lighter colours. Because these are “interior” details, I only use a 1 pixel stroke.

Logically, the features would be next; but they will be the bit that really makes a difference, so I’m leaving them ‘til last. The arm is easy, and it doesn’t interfere with the features, so we’ll do that next.

New layer, new profile.

The hand and arm went on the same layer. I drew the hand first as new objects always go on top of old ones. If you find you have drawn things in the wrong order, you can always use the object selection tool () to pick them and use the Object->Raise or Object->Lower menu commands to get the order right.

All that’s left is the features. For this stylised appearance I’m just doing eyebrows, eyes, nostrils and mouth. Again, they appear inside the main outline of the face, so just a 1 pixel outline.

All that’s left to do is put in a background layer, just above the photograph, and add a big rectangle filled with a gradient.

Gradients

Make the “photograph” layer current and select Layer->Add layer from the menu - call it "background". Now select the rectangle tool () and drag out a rectangle big enough to cover the whole page.

On the Fill and Stroke dialog, select the Fill tab and click on the Linear gradient icon. Your rectangle will get a gradient fill and a new line will appear that shows the start and end points of the gradient:

The control points (circled) can be used to change the scope of the gradient. Click on the gradient edit tool () then drag the points around to change the gradient.

You will see that the toolbar at the top of the window has also changed.

There are options for creating a new gradient, a pull-down list of all the gradients defined in the document and options to duplicate and edit the current gradient. Click the Edit… button to show the Gradient Editor.

A gradient consists of a number of “stops” that have a colour and opacity. The first thing on the window is a preview of how the gradient looks over a grey checker-board pattern. Next is a pull-down of all the stops in the gradient; use it now to select the second stop:

By default, this will be the same colour as the first stop but with zero opacity. Like the solid colours, you can use the colour wheel to pick a different colour and the “A” slider to alter the opacity. The Offset slider can be used to position interim stops if there are more than two.

So now we have our finished picture. You may be able to tell that I’ve tweaked some of the profiles a little.

Saving

You should probably have done this already, but it is time to save the picture. Inkscape works with SVG (Scalable Vector Graphic) files. If you select File->Save, this is what will be saved.

It may surprise you to know that the SVG file consists only of text that describes the various elements you have created; it is up to the software to make sense of the instructions and draw the picture. This makes it extremely efficient – this tutorial file is only 28KB, and will remain 28KB whether we want to view it as a 320x240 image or a 2048x1536 image. And because it’s created from vector instructions, it won’t go blocky when you make it bigger or blurry when you make it smaller.

Unfortunately, at present there are very few applications that can handle SVG files; Firefox can view them, but it doesn’t handle some of the functions such as blurring, and it doesn’t show them within HTML documents (web pages).

So, if we want to make use of our picture elsewhere, we need to save it as another format. Inkscape allows you to export the picture as a PNG (Portable Network Graphics) file. This format of file can be rendered by most web browsers, and can also be read into other graphics packages such as GIMP, Paint.net or Paint Shop Pro and then saved as yet more formats such as GIF or JPEG.

Select File->Export Bitmap from the menu.

You can choose how much of the picture will be exported with the buttons along the top. Page will just export what is contained within the bounds of the page (what we want), Drawing will include all of the objects you have drawn, Selection will just do the selected object and Custom will allow you to define an area to export. You can use the Bitmap size options to change the final size of the image. For example, if you change the dpi from 90 to 300 (print quality) you will get a 3413x2560 image.

Click the Browse button to pick a file name and then Export to create the PNG.

You can see from the final file sizes just how efficient the SVG format is. The 90dpi file is 122KB and the 300dpi one is 487KB. However, you can also see that the quality is not compromised by making it bigger.

The final file is available here: pop-tutorial.svg

The End