Essential watercolour tips for urban sketchers

Essential Watercolour Painting Tips for Urban Sketchers

In this post, we will explore how to use watercolour paint as an urban sketcher. Urban sketching with watercolours is a unique skill and while many of the ideas in this post can be applied to using watercolour paint traditionally too, we will focus on the essential tips that will help you when painting on location. 

Why is watercolour painting difficult to learn?

Watercolour painting can be a tricky skill to pick up, it’s an intimidating medium as we are at the mercy of how the water and the paint behave on the paper, which is something even the best watercolourists can’t always anticipate. It’s also part of the fun.

Using watercolour while urban sketching can be trickier still.

I want to help you overcome any intimidation you may feel so that you can apply the paint with courage and master working with the paint rather than against it.

Traditional Watercolour Painting vs Urban Sketching

There is a big difference between how traditional watercolour painters working in a home or studio environment may use watercolour paint versus how an urban sketcher, who is painting on location, uses watercolour paint.

Liz Steel explores this in her blog post here.

Essentially we, as urban sketchers, do not operate in the same way as a traditional watercolour painter would when we are using watercolour on location. Urban sketchers usually have less time to plan and to paint, fewer tools and an uncontrollable environment, yet we have less pressure in the sense that we are just sketching and not trying to produce a work of fine art to hang on the wall.

I believe there are some urban sketchers that blur the lines of these two different camps. Someone who instantly springs to mind is Marc Taro Holmes.

Marc brings the vibe of a traditional studio artist to urban sketching. There are some urban sketchers who are almost ‘plein air painters’ in that they may set up in one place with an easel and spend a couple of hours painting a scene.

In this post, we are considering using watercolour as an urban sketcher capturing quick sketches of the world around us.

Materials for Watercolour Urban Sketching

You will read many an article or hear advice that you should buy the best materials you can afford when it comes to watercolour painting. To some extent, I agree.

However, when you are just starting to learn a skill such as watercolour painting, sometimes having more expensive materials can actually hinder your progress.

If you are anything like me, expensive things intimidate me! That probably sounds a bit weird. Hear me out.

If I have a very expensive sketchbook or paper (like the Arches watercolour block I just bought to do commissions on) you are scared of “wasting” it and you tighten up. The same if you have very expensive professional watercolours – you will be afraid to use them. 

It seems, at least in my experience, that the expense of something effects the ability to play, experiment and be brave.  And these things are exactly what you need to do and be when you are painting in watercolours.  

I think as you progress and get a little more confident in your abilities, that’s the point to upgrade your materials. Not all art materials in the same price bracket are made equal, however. You may have got this impression already if you’ve read my posts on which watercolour sketchbooks or watercolour paint sets I recommend.

For day to day watercolour urban sketching, you need:

  • watercolour paper in a pad or book format which you can chuck in your bag, carry everywhere with you, that you are not concerned about using or getting a bit dog-eared and that can handle both drawing and watercolours without turning into a soggy mess
  • 12 pans (slightly more or less is fine, 36 is overkill) of colour in a small plastic or metal box with room to mix colours in the lid
  • round brushes (try size #2, #6 and #10), a flat brush (not essential but great for painting straight edges, a dagger brush (not essential but so versatile)! Synthetic, natural hair or a blend is fine…do not overthink this, just get brushes you can afford but not super cheap craft-type brushes that may be labelled as watercolour brushes and have 10 in a packet. These are not good. Get the real deal.

Essential Tips to Improve Your Watercolour Painting

Sketch Lightly

If you are doing a watercolour-only painting, sketch very lightly. Heavy pencil lines and heavy erasing will ruin the paper surface, so when you go to paint over the top, the paper will either reject the paint, or the surface will be much thinner and your paper will wrinkle more than in other places. Obviously as urban sketchers we are not looking to create a perfect finished piece but its a good habit to get into. And you definitely don’t want to damage your paper surface.

Do you want to learn how to sketch your own adventures in ink & watercolour?


I will show you my exact sketching process in ink and watercolour. I have travelled around the world in the last 3 years and this is my go-to system of creating beautiful yet quirky illustrations to capture the magic of my discoveries.

We will work through 3 projects, step by step (pictured below), all of which are real-life examples of things I have sketched along my travels. I provide the photo references you can work from.
We will start by choosing a composition, laying in the initial pencil sketch, adding ink lines, layering watercolour and adding the final touches.
This and much more are included in my course, Sketch Your Adventures, click the button under the image to find out more!

Sketch your adventures modules

Paint very light initial layers

Watercolour painting is all about working in layers. As you can’t paint light colours over dark colours (like you can with opaque mediums such as acrylic and oil) you need to plan your painting a little more. You need to understand where your lightest lights will be and your darkest darks.

Leave white space

To achieve depth and contrast in your painting, leave some white space where your highlights will be. This is tricky to get used to at first but keep practising identifying where those highlights go in each sketch and avoid painting them at all.

Paint a scene with strong contrast

Painting a scene with very strong lights and darks is really going to help us paint a dynamic painting with lots of depth. If you are out sketching on a dull overcast day this is going to be tricky. If the sun comes out at any point to create shadows, make sure you grab a photo so you can refer back to it later. Strong lights and shadows are the keys to making any watercolour sketch pop off the page.

Mix your dark colours

Do not use black straight from the pan or tube, in fact, just get rid of your black pigment, you don’t need it. You can make super interesting dark colours mixing pigments such as Ultramarine (blue) and Burnt Sienna (brown) together.

Make a watercolour mixing chart

Make it from your paint set and make it in your sketchbook. This is such an invaluable tool to understand how your paints work together and a reference tool to help you get the right colours in your sketch every time. Don’t know how to make a watercolour mixing chart? Check out my post here or the video below.

Learn how to mix colours

Following on from making a mixing chart, it is important to learn how to mix colours correctly. If you mix more than 3 colours, for example, it’s likely you are going to achieve a horrible muddy colour.

Learning how colours mix and work together is one of the most important pieces of knowledge you can have when it comes to watercolour (or working with colour in any format).

If you would like some practical information about colour theory for urban sketching, check out my post here.

Be brave with your colours

When painting urban scenes it can be easy to look and just see beige and grey, boring. However, look again. Is that red and oranges you see in the roof, blues and purples in the shadows, pinks in the sky, yellows and greens in the window reflections?

Ok, perhaps don’t use all of those colours in one scene.

The point is to be expressive with your use of colour, don’t be afraid to stylise the scene. You can use spots of local colour (i.e. colour that is really there) but you can spice things up with colours you feel are there.

Ian Fennelly is the master of this approach. I also love how Liz Steel uses ‘Potters Pink’ in a lot of her work – it’s so distinctive. When I see that colour, I think of Liz Steel.

Get loose and splashy

We are sketching, not producing fine works of art to hang on the wall (probably), so don’t be afraid to throw the paint around a bit.

If you have quite a tight ink drawing, using splashes of watercolour over the top can be a really interesting counterpoint, adding drama.

Think of urban sketchers like Simone Ridyard who does 95% line drawing and then adds a small splash of colour, usually in just one area and usually a bright red or a blue.

Ian Fennelly gets some very light lines down on his paper and then splashes on some watercolour here and there, all the while working layer after layer to build the sketch up from basic big shapes in light washes to finer details with bolder colours.

Do not get disheartened

Keep working on it. I make the mistake often when I’m halfway through and think to myself “it looks rubbish”.

Every single sketch or painting goes through a period where it just looks rubbish. Those early layers have to be painted though. It takes time. You need to be patient. You need to layer your painting or sketch.

We tend to see finished sketches and end results and judge our efforts against these. However, if you take a class with Ian Fennelly or any urban sketcher you will witness a period of the painting where the first wash of colour goes on and for a significant amount of time the painting looks lacklustre. This is when you absolutely need to keep going, push through and keep working. By the end (and you decide when that is by the way), you will see a very different result. Don’t give up too soon!

Check out my ebooks with hundreds of ink & watercolour travel sketches from all over the world. Get some inspiration for your next trip…

Common Mistakes or Problems in Watercolour Painting

Mixing muddy colours

Be careful which and how many colours you mix together otherwise you could end up with muddy colours. Try not to mix more than 2 colours together. If you have made a watercolour mixing chart then refer to it regularly to identify which colours in your set will give you the colour you need. After time, you probably won’t feel the need to refer to the chart as know which colours to mix will become instinctual.

Not letting the paint dry

I never seem to learn this lesson. If are not patient and do not let your paint dry properly your colours may bleed together or you may produce ‘back runs’ where the water runs into your pigment and produces a puddle of fainter colour where it’s washed away some pigment.

Sometimes we want to produce these sorts of results but not unintentionally!

Overworking the painting

It is possible to overwork a watercolour painting. While painting in layers is the key to producing depth, you do not want to use too may unnecessary layers. Each layer you apply can cause the paint of the previous layer to lift and you are at risk of things becoming a bit muddy.

Watercolours are not meant to be used for super detailed paintings, embrace the nature of the medium.

Some of my favourite online classes

Why does my watercolour painting look flat?

Creating depth and contrast in a watercolour sketch or painting are the keys to ending up with a dynamic piece.

Depth is when a painting on a two-dimensional surface feels three dimensional. The way to achieve depth is to use light and shadow to create the illusion of three-dimensional objects within the painting.

To create depth you need to consider the composition of your sketch. Are there elements in the background, mid-ground and foreground? 

Contrast is the difference between the lightest values and the darkest values.

Elements in the background are going to be a much lighter value than elements in the foreground. As watercolour painters this helps us, we can work from the background of our painting in light values moving to the mid-ground with slightly stronger values and then working on the foreground with darker values. This creates both a sense of depth and contrast.

Final Thoughts

I hope this post has been useful to help you identify the challenges of watercolour sketching and how to address them. Watercolour is such an amazing medium, the fun of using it is exactly because you cannot anticipate quite what it will do! We can do our best to harness it though and produce sketches using watercolour to best of our abilities.

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