This 12 set is really all you need. I once went to their shop in the Lake District and bought lots of other colours to add to my kit, but have taken most of them out again, because these colours are so well chosen.
Inktense pencils are absolutely perfect for sketching on the go. I just love the way you can combine dynamic drawing with painterly mark-making and fill the page with vibrant colour, while carrying almost no kit - just a handful of pencils and a waterbrush.
I tried them out on a recent sketchcrawl. It was one if my residency days, taking my volunteer group of academic newbie-sketchers out of the safety of the university, to draw in the big wide world for the first time. We didn't go far, just down the road to the Manchester Museum, the same place I took my Urban Sketchers last week.
The Graphitint are similar to my Inktense pencils, because of being soluble, so I used the same technique - vigorous mark-making followed by quick, understated gestures with a waterbrush - but the Graphitint pencils were different to use in three important ways.
Firstly, the lead is softer than either Inktense or any regular watercolour pencils I have tried before, giving a thicker line which you can see really picked up the grainy surface of the watercolour paper, creating a slightly looser, more textured result:
Secondly, whereas the Inktense are extremely vibrant and explode into colour when you add the water, the Graphitint are far more understated: certainly the set I was given were slightly muted shades, which work well together to create a softer overall effect, whereas the Inktense tend to be more contrasting and zingy.
Lastly, the Graphitint colour doesn't change when wet, it just dissolves. Though less exciting than the Inktense, this makes them more predictable and so slightly easier to manage. It is less easy to 'overdo it' - with the Inktense pencils, if you apply too much pencil work before the water, you can quickly get into a mess. It just depends what you are after.