Re: [Gimp-user] Changing the brush sizes

[Steve Kinney <admin pilobilus net>]

On 06/13/2016 10:05 PM, Jim Horrocks wrote:
> How do you change the sizes of a brush? I knew but have been away from gimp
> for a little while and my memory not so good, now I can't remember what it
> is. Looking forward to hearing from the helpful users of gimp. I'm using 2.8

There are simpler answers than this, but here's a post I made about
changing brush sizes (and hardness) a couple of weeks ago:

I do a lot of photo editing and image authoring, so I spend a lot of
time using Brush type tools in the GIMP.  When I discovered that brushes
can be resized "on the fly" via mouse + keyboard commands, my workflow
changed radically - more speed, more precision, less stress.  Changing
brush hardness the same way completes the picture of a happier me.

A GIMP VBR variable brush scales with "perfect" resolution and has
adjustable hardness because it is a vector, not a bitmap.  The VBR
brushes available in the basic set included with the GIMP did not suit
me, so I made a few of my own:  A circle, four ellipses with different
orientations, a square and a diamond.  Making them with the GIMP brush
editor is trivially easy, but here they are for e-z download and
installation:

http://pilobilus.net/xfer/brushes.png

http://pilobilus.net/xfer/Variable-Brushes.zip

Just extract the brushes into your local ./.gimp2.8/brushes/ directory
(or wherever yours is located), start the GIMP and open the brushes
dialog:  If you have not named any other brushes with strings of leading
zeroes, the seven new variable brushes should be at the top of the list.
 (If you want them elsewhere, rename them; the GIMP sorts brushes
alphabetically by file name.)

A set of general purpose GIMP variable brushes is only useful if you can
"vary" them on demand.  For that, configure this:

Go to Edit > Preferences > Input Controllers.  Double click Main Mouse
Wheel in the right pane in the dialog window to open its configuration
dialog.  You can chose other keyboard combinations if desired, these
work well for me:

Find the Scroll Up (Alt) item in the list.  Double click on it to change
the default setting if any, and use the search box to find "Increase
Brush Size."  Double click this item in the list to set it.  The top
dialog box will close, leaving the General - Mouse Wheel one open.

As above, find and set the following options:

Scroll Up (Ctrl-Alt) - Decrease Hardness
Scroll Down (Alt) - Decrease Brush Size
Scroll Down (Ctrl-Alt) - Increase Hardness

That's it:  Close out of the confifiguration menu and check out the
variable brushes by painting in black on a white canvas:  I find the
keyboard command options I list easy to remember and and use.  Your
mileage may vary and if so, you can choose different keyboard and mouse
wheel combinations.

I find the set of brushes provided above ideal for generic use (round),
getting into tight corners (the ovals), and following rectilinear
contours (the square & diamond).  You may want different brushes; check
out the GIMP brush editor and soon you will be making variable brushes
suited to your unique needs.

Brushes etc. are hereby released under cc share-alike license, use them
freely for any lawful or other purpose.

:o)

Steve