added reasons 1

_subsections/chapter04.org

@@ -27,6 +27,22 @@ so select the layer mask and draw with black on the center panel to hide or show
 - hold the alt/opt key and click on the layer mask
 - you can also click on any other layer, or outside the layer mask to hide it
 
+** reason 1: non destructive abilities
+while you can certainly delete parts of an image and putting something else in it's place, you cannot undo that deletion so easily.
+
+1. select the area you want to show
+2. hit the mask button (this will automatically hide everything not selected)
+
+*** hide the selected area (2 methods)
+
+**** method 1
+1. selecte the area you want to hide
+2. select->inverse
+3. hit the mask button
+
+**** method 2
+1. select the area you want to hide
+2. ALT/OPT + mask button
 
 * Playlist
 
@@ -34,7 +50,7 @@ so select the layer mask and draw with black on the center panel to hide or show
 + [[https://youtu.be/aNpO6G72O3w?si=OYj36t6pnG6zpXIm][00:00 What Are Layer Masks?]]
 + [[https://youtu.be/aNpO6G72O3w?si=CaHdFgVM5pw_fgp0&t=178][02:58 Important Downloads & Announcements]]
 + [[https://youtu.be/aNpO6G72O3w?si=pwKG3NNXzp8NsGN-&t=209][03:29 Why Use A Layer Mask?]]
-+ [[https://youtu.be/aNpO6G72O3w?si=D0ZVdRvBZ9jrjm-n&t=227][03:47 Reason 1: Non-Destructive Abilities]]
++ [[https://youtu.be/aNpO6G72O3w?si=D0ZVdRvBZ9jrjm-n&t=227][03:47 Reason 1: Non-Destructive Abilities]] *current*
 + [[https://youtu.be/aNpO6G72O3w?si=w8aLyeLpyyqeX5G9&t=474][07:54 Reason 2: Compatibility with Non-Raster Layer]]
 + [[https://youtu.be/aNpO6G72O3w?si=cHwwjgjcbIvf3Hno&t=686][11:26 Linking & Unlinking Layer Masks]]
 + [[https://youtu.be/aNpO6G72O3w?si=sDBGUsD5CKK_0i1g&t=813][13:33 Turning Off and On]]