Seals have to be some of the most adorable animals on the planet. From their ‘sea sausage’ physique, to the way they flop around on land and especially their big pleading eyes, you just have to melt. I’m going to draw one inside of Adobe Illustrator using a simple sketch. My process is as simple as can be (very similar to what we saw on my Magical Cat process) and can be applied to any drawing you may have on hand. I have quickly drawn a very rough sketch of a cute seal or sea lion that I’d like to vectorise and use on a t-shirt. I’ll be using Adobe Illustrator as the primary program, but my techniques can easily be applied to other applications as I don’t rely on program-exclusive features.


1. Cleaning up the seal sketch in Adobe Photoshop

It’s going to be much easier for me to trace over my seal image in AI when the image is clear and dark. For this first step in the process, I use Adobe Photoshop, however it is completely possible to do this in any other graphics program. The rough sketch is never going to be as clean as the finished product, however, by simply going to Adjustments > Levels or Adjustments > Brightness/Contrast, I can darken up my drawing so that its details stand out further.


Seal in Sketchbook

Using the polygonal lasso tool to separate the seal from the rest of my sketches


You’ll also note that I am using the Polygonal Lasso tool to make a selection around the seal. This enables me to copy and paste this area of my canvas specifically and paste in the isolated drawing on a new canvas. I save this drawing out as a .jpg and open Adobe Illustrator to begin the next steps.


2. Using Adobe Illustrator to prepare the seal drawing

Now that I have my cleaned up seal sketch, I create a new file in Adobe Illustrator at my preferred size and drag in my sketch from an open folder.

Creating seal file in Adobe Illustrator

Creating a new file in Adobe Illustrator

Generally, when tracing over images to create illustrations, I use:

  • The Pen tool to create areas of color and flowing shapes
  • The shape tools (found in the tools panel) to create simple geometric forms
  • The pathfinder window and unite operation to combine shapes into one compound form

I also, in the case of more ‘artistic’ illustrations like this seal, make use of a drawing tablet to add dark and light values. My current tablet is a very small (admittedly old) Wacom Intuos (small), which is fairly economically priced compared to some other models. While I also own a medium-sized Intuos, I find that the small size and light weight of this model makes it ideal for carrying around with me.

A Wacom Intuos tablet on my desk

A standard small size Intuos Wacom tablet


3. Creating areas of colour in Adobe Illustrator

I’m going to start using the pen tool to trace over my seal image. Before I start, I always make sure to click the ‘lock’ icon over my original sketch so that I cannot accidentally click it with the select tool. One useful way of keeping all your shape and colour areas organised is to separate them into different layers – so, a base colour layer, a shadow layer, a highlight layer, and layers for the background. Because each path is its own object inside of Adobe Illustrator, this simple technique can assist you in controlling all of the elements in an image. You can always move the objects into one single layer or group later on.

Starting our drawing in Adobe Illustrator

Using the ‘Lock’ icon to prevent accidental moving or editing of the original sketch


Pen tool in Adobe Illustrator

Using the pen tool to create the basic seal shape


Changing the opacity in Adobe Illustrator

Changing the opacity of the shape to more easily see the sketch underneath


Creating seal eyes in Adobe Illustrator

Creating the seal’s eyes using basic shapes. I manipulate the bezier curves of this shape to match the original sketch. The same procedure will be repeated for the other eye.


Creating a seal's nose using the pen tool

Using the pen tool and bezier curves to create the seal’s nose


Creating layers in Adobe Illustrator

Creating new layers for the shadow and highlight sections of the drawing. This helps to organise our Adobe Illustrator file.


4. Adding ice, water and sky to the drawing

This seal is just floating on a white canvas right now. I need to add something for him to lounge around on. Using the pen and shape tools once more, I create outlines for the ice, sea and sky. Once these base layers are established I use my Wacom Tablet to add organic details. Adding so much detail using the pen tool would be a little difficult and time-consuming, but the brush tool allows me to create lots of detail with a stroke of the stylus. I can change the smoothness of the brush stroke using the panel or expand the appearance of these strokes if I want more fine control.


Creating a paintbrush in Adobe Illustrator

Creating a new paintbrush in Adobe Illustrator to paint on areas of more ‘painterly’ detail like highlights and fur


New calligraphic brush in Adobe Illustrator

Selecting ‘New brush’ inside of the brush pane


Changing brush size, angle and pressure in Adobe Illustrator

Changing brush angle, pressure and size in Adobe Illustrator. Best used with drawing tablets and styluses.


Changing smoothness and fidelity in Adobe Illustrator

Double-click the brush icon to change the fidelity and smoothness of brush strokes. These values will determine how faithfully your line is drawn in Illustrator and how sharp the corners are.


Finishing the seal drawing in Adobe Illustrator

Creating sea, ice and sky with highlights and shadows

5. Mocking up the final product

I use the ellipse tool to drag a large circle over the seal, and then select both it and the layers underneath it. I right click and select ‘Create clipping mask’. This is similar to layer masks in Photoshop and essentially hides everything that is outside of the clipping mask shape, in this case, the circle. Once that is complete, I select all and copy + paste as special inside of Photoshop. This allows the seal to be scaled up or down as an imported vector, rather than as a raster image. I also create a quick mock-up of how Shulkie the Seal will look on a t-shirt so I can use it as an example in my portfolio for myself and others. Done!


Shulkie the Seal

The finished seal. Super cute!


Mocking up an image on a t-shirt

Adding the image as a digital mock-up to a T-shirt, easily done by copy+pasting on an image in Photoshop. Easy and fast!