[Gimp-user] Layer masks

[Dede1943 <forums gimpusers com>]

Greetings,

I am a new user to Gimp. I am using Gimp 2.8.14 with Yosemite on an iMac. I have
been reviewing YouTube videos and reading other tutorial material on using Layer
Masks. There is one video ( https://www.youtube.com/watch?v=9ErchKGzsNc  ) which
I understand and follow as to the instructive use of Layer Masks but can not
duplicate on my current system. I have followed other tutorials and can
replicate the process demonstrated in them (
http://blog.patdavid.net/2011/10/getting-around-in-gimp-layer-masks.html) and it
appears that the instructions are similar but the process does not yield the
expected results on my system. Consequently, I am a bit confused on how to
invoke Layer Masks and use them constructively to manage my images ( mostly
digital phots).
The video (  ), if I understand it correctly, instructs one to:

1.Open the image. 
2.Make a back up copy in layers.
a. (since the second layer automatically adds a Alph Channel, I did not add one)
3.Select and activate the copy and add the Layer Mask.
4.Make sure the Layer Mask icon is highlighted and activated in the Layer
dialog.
5.Select the paintbrush making sure that Black is selected as the Foreground
color.
6.Brushing along any area of the image to select it should reveal the
transparency layer but does not. I can see the black lines, I'm drawing on the
center image on the Layer Mask icon in the Layers dialog, which is white.


I don't know if I creating a problem with the brush selection but the brushes
work otherwise. The Alpha Channel does show up in the Channel Dialog box, so I
know Alph Channel is present for the image.
I have reviewed some problem solving for Gimp not performing as expected and
have made sure that “Show Selection” is activated in the View Menu.


Any thoughts or suggestions will be appreciated,
Henry

-- 
Dede1943 (via www.gimpusers.com/forums)