Painting Thin Lines and Fat over Lean – a blog question

I had a question from one of my Blog visitors a short while ago and thought my answer might be of use to others, so here it is –

Here’s the question

“Hi Jason,
Thanks for putting this up. Excellent info. I have some additional questions though.
I was wondering how you deal with the lean and fat rule in oil-painting since you mention a wash over previous layers. Also can you give some information about the consistency of the paint you use for whiskers? I always have trouble with these long, clean curvy lines, even with a rigger brush. The paint just doesn’t flow from the brush and when I thin the paint to improve the flow it becomes too transparent.
How fast do you paint 1 whisker, is it a quick swoosh of the brush or do you slowly drag the brush along the surface.? Hope you have some tips because these are the things that you normally don’t read in tutorials”.

Here’s my answer

“Good questions, I use Alkyd Oils which dry quite fast and hard, and currently I thin my paints with an Alkyd type thinner (I’ll find out the make and post here), similar to Liquin, which improves the flow when required, I’m not using any other oils etc so I think that takes care of any fat over lean type stuff.

I honestly don’t worry about that stuff too much myself, as I’m not doing anything to excess.

If I need the paint to slip / flow even more, eg when painting whiskers, I will also add a little odorless paint thinners to the mix. So to paint a whisker I would get some paint (white for instance) dip my brush in alkyd thinners, mix it a bit, then dip my brush in a little odourless thinners and mix that in too.

There is a fine line between too little and too much alkyd thinners and odourless thinners, which as you have found, will cause the transparency of the paint. Practice is the only way to really know.

I paint a whisker in one movement, at a moderate speed approx 1 second to do 5-6 inches.

Sometime, but not always I will need to carefully go over the whisker a 2nd time to make it nice and opaque (let the 1st layer dry 1st).

One important thing to consider is the texture of the surface you are painting on, ie if you are using a rough grade canvas it will be VERY difficult to get a nice even flowing line, when compared to a finely sanded board, for instance.

I use a fine grade canvas – often called a portrait canvas.

To make it even finer you could paint an additional layer of gesso on top, let dry fully then sand with some very fine sand / glass paper”. This will certainly make painting flowing lines MUCH easier.

Alternatively prepare your own painting panels out of MDF (UK term I think) and a few coats of Gesso, sanding between coats. This is certainly the easiest surface to paint flowing lines on and is great untill you get a lot of experience.

Hope that helps