[gimp-book-painting] Added a topic to paintbrush and airbrush tool...

[Americo Gobbo <amerigo src gnome org>]

commit 260e69137c0b6f36ec433a2115aad6b183fc0ebf
Author: Americo Gobbo <jag rabisco gmail com>
Date:   Fri Jul 6 17:15:37 2018 -0300

    Added a topic to paintbrush and airbrush tool...

 parametric-brushes.md | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/parametric-brushes.md b/parametric-brushes.md
index b363e87..c19f7ed 100644
--- a/parametric-brushes.md
+++ b/parametric-brushes.md
@@ -25,8 +25,10 @@ Basically the paint dynamic emulates the technique and the brush emulates the st
 
 <figure><img src="parametric-brushes.assets/parametric-brushes-deveze-dry-media-test.png" width="640" 
title="Dry Media by Gustavo Deveze" /><br><figcaption>Gustavo Deveze drawing with the Dry Media paint 
dynamics with the brush set of parametric brushes.</figcaption></figure>
 
-To explore I have revised a bit the Pencil Generic Paint Dynamics
-to adapt better it to other dry media and it is 
[here.](parametric-brushes.assets/parametric-brushes-Dry-Media.zip "Dry Media Paint Dynamics")
+#### Paintbrush and Airbrush Tool
+To explore the dry media effects with parametric brushes, I have revised a bit the Pencil Generic Paint 
Dynamics
+to adapt better it to other dry media and it is 
[here.](parametric-brushes.assets/parametric-brushes-Dry-Media.zip "Dry Media Paint Dynamics").
+Is possible to use different tools, pencil, paintbrush and airbrush, but, effectively the airbrush is more 
interesting.
 
 <figure><img src="parametric-brushes.assets/parametric-brushes-paintbrush-test.png" width="640" 
title="Parametric brush with Dry Media Paint Dynamics  - Paintbrush Tool" /><br><figcaption>Samples using 
Paintbrush tool with all parametric brushes of the set, shared on Download topic, using my paint dynamic Dry 
Media.</figcaption></figure>