Creating quick fine lines very close together can easily be achieved by using the Comber brush, when worked swiftly, it gives the effect of lots of tiny strokes. The flat serrated edge allows beautiful, organic marks. I use this brush in many of my paintings, when painting fur, feathers, grass details and adding texture to water.
The comber brush is available to purchase here
This brush enables you to quickly add lots of small line details when painting ripples and reflections on water too. Watch my YouTube video 'Painting a reflection on a lake' here.
It can be used on it's side to create individual lines or flat using all the bristles to enable lots of individual lines or dots.
By using the very tips of the bristles you can add clusters of tiny dots, this worked really well when painting the Horse's muzzle as well as on the fur, creating longer finer lines.
It's important to remember you don't need to add much paint onto the brush, the drier the brush the better. Using hardly any pressure you can create very subtle yet striking effects with this brush. However when creating longer, finer lines, adding a thinner will assist with the flow of the paint., making sure the lines go on smoothly and unbroken.
The series 5 Comber Brush is available in two sizes in my online store.
Why don't you give this a try, you'll be pleasantly surprised how effectively this brush can be used in your paintings.