Lesson 4: Layer
Basics
Beginners often see Photoshop as a simple digital version of a painting canvas
or
photograph.
I
t
s
important
for students to move beyond that view to
understand
that a Photoshop document can be
structured
using layers, and the advantages of
doing so.
Goals
for this lesson
In this lesson, students begin to think of Photoshop files as
structured do
c
umen
t
s
with parts (layers) that can be edited independently. Students will gain from
under-
standing that layers give them the flexibility to change their mind at any time,
ad
a
pt
work at the last minute to
incorporate client-requested
changes, leverage files
t
o
create alternate versions of an image within the same
file,
and to do other things
t
ha
t
would be a great deal more trouble on a real paint canvas or in a
dar
k
r
oom.
After completing this lesson, students should be able to correctly explain the
f
ollo
w
–
ing concepts and to describe their
importance
or relationships to other aspects of
the
le
sson:
Basic types of
layers:
background, image, text,
adju
stmen
t
Transparency (transparent
pi
x
e
l
s)
Opacity
(semi-transparency
of
pi
x
e
l
s)
Blending modes (how a
l
ayer s colors combine with layers behind
it)
Stacking order of
l
ayers
Layer
g
r
oup
s
Visible layers and hidden
l
ayers
Active (selected) layers and inactive
l
ayers
Getting
S
tar
t
ed
Now that the students have completed a few lessons, many of them probably feel
confident enough to start up Photoshop without even reading the Getting
S
t
ar
t
e
d
section at the beginning of each lesson. Reinforce the idea of restoring defa
ult
preferences at the beginning of each lesson so that they see what the book
de
sc
r
ibes
.
Additionally, the Getting Started section shows them what
t
he
y
ll
be creating. I
t
can be helpful to have the
le
ss
on
s final image in your mind as you work through
t
he
steps in the lesson.
26
INSTRUCTOR
NO
TES
S
elec
ting
layers
One common stumbling block for the novice Photoshop user is forgetting that a
layer must be active (selected) in order to be c
hang
ed.
Sometimes students who are used to working in applications such as
A
dob
e
Illustrator or Adobe InDesign think that they can just click an item to make its
l
ayer
active. For example, a student might assume that clicking the beach or the
flo
wer
would switch the active layer to the one containing that subject matter. If
studen
t
s
are interested in working that way, you can let them know that
it
s possible by
selecting the Move tool and turning on Auto-Select in the options bar. But
studen
t
s
should
understand
that they still need to make sure the layer they want was se
le
c
t
e
d
by
Auto-Select another
layer can become selected by accident because
A
ut
o-
S
e
le
c
t
can select
semitransparent
pixels of a layer.
In the Layers panel, managing layer selections can be tedious when the layer list is
long. If this happens you can direct students to the layer selection commands
under
the Select menu. The Select All Layers and Deselect Layers commands are
par
tic
u
–
larly
u
s
ef
ul.
Rela
t
ed
exercises
or demonstrations
To
demonstrate
the
importance
of knowing which layer is active, have
studen
t
s
make changes on a layer of a multilayer image and then use the layer visibility ic
ons
to view the c
hang
es
.
One easy and dramatic way to do this is to make a duplicate layer of a
si
ng
le-layer
image file by dragging the original layer onto the New Layer icon at the bottom of
the Layers panel. Then, in the Layers panel, select the lower layer so that it is
t
he
active layer. Select any color from the Swatches panel and then drag the Brush
t
o
ol
around the image. Because the active (lower) layer is hidden behind the
dupl
ica
t
e
layer, the display in the document window appears unchanged. However,
when
you click the eye icon for the upper layer to hide it, the paint strokes you made
ar
e
revealed on the lower layer.
You can set up another
demonstration
by selecting half an image and
choosing
Layer > New > Layer Via Cut so that half the original image is on one layer and half
on another. Then create a selection border that overlaps the boundary
b
e
twe
en
the two halves. When you make changes (such as to move, transform paint,
bu
r
n,
or dodge) to or within the selection, ask your students to explain why you get
t
he
results you
do.
The 2018 release of Photoshop added the ability to copy and paste layers using
t
he
Edit > Copy and Edit > Paste commands, when one or more layers is selected
i
n
the
Layers panel. This is a useful alternative to dragging layers between
open
documents, especially for those who like to use keyboard shortcuts. Also, c
op
y
i
ng
ADOBE PHOTOSHOP CLASSROOM IN A BOOK (2022 RELEASE)
27
and pasting selected layers within the same document is a new alternative to
t
he
Duplicate Layer command. The Edit > Cut command does not operate on se
le
c
t
e
d
layers, so when using the Copy and Paste commands to rearrange layers within
t
he
same document, remember that the pasted layers are duplicates, so the original lay-
ers might need to be
de
le
t
ed.
If you expect your students to use Photoshop for work that might result in a very
long list of layers, such as the design of web or video assets, you can point out
t
he
filter near the top of the Layers panel. For example, you can open the Lesson 13 file
13End.psd and
demonstrate
how to use the Layers panel filter to show only
l
ayers
with specific names, effects, or a
t
tr
ibut
es
.
Changes
to
proportional scaling
A series of changes to
proportional
scaling in Photoshop may confuse students
w
it
h
prior experience using other software or earlier versions of P
hot
o
s
hop.
To scale a selection while maintaining the original
proportions
of the selection
i
n
versions up to Photoshop CC 2018, it was necessary to hold down the Shift key
while dragging a handle of a
transformation
bounding box. In the 2019 release of
Photoshop, dragging a handle scaled the selection by default, and pressing Shi
f
t
scaled
disproportionately.
This change was consistent with newer applications
t
ha
t
scale
proportionally
by default. However, it was not c
onsi
sten
t
:
Some P
hot
o
s
hop
object types such as type, shape layers, and type layers did not scale
pr
opor
tionally
by default, and this confused many
u
s
ers
.
In Photoshop 2020, Adobe improved the consistency of this feature. Dragging a
transformation
bounding box handle now scales
proportionally
in almost all cases
.
In addition, the default can now be controlled by the Maintain Aspect Ratio
but
t
on
(the link icon between the W and H options) in the options bar. When a
transf
or
ma
–
tion bounding box is active, the Maintain Aspect Ratio is selected when
b
ou
nd
i
ng
box scaling is
proportional.
If a student wants scaling to be
non-proportional
by
default, they can deselect the Maintain Aspect Ratio button. Either way, Shi
f
t
–
dragging a bounding box handle temporarily reverses the setting of the
M
ai
n
t
ai
n
Aspect Ratio link ic
on.
Despite the fact that
proportional
scaling works more consistently in P
hot
o
s
hop
2020 and later,
proportional
scaling by default may still be awkward for
studen
t
s
using multiple Adobe applications such as InDesign and Illustrator. In those a
ppl
ica
–
tions, the Shift key is still required to scale an object
proportionally
by dragging a
bounding box handle. If this inconsistency is difficult for those students, you c
an
suggest that they enable Use Legacy Free Transform in Preferences > G
eneral.
28
INSTRUCTOR
NO
TES
Adding
t
e
x
t
Starting in the 2019 release of Photoshop, creating a text layer by clicking any
T
y
p
e
tool now creates placeholder Lorem ipsum text in the new text layer. The text is
selected by default so the student can immediately type over it with their own
t
e
x
t
.
Previous versions of Photoshop created empty new text layers.
Caution students that the single-key tool shortcuts in Photoshop (such as V
f
or
Move tool, C for Crop tool)
don
t
work when entering text because they enter c
har
–
acters in that mode. Make sure they learn how to exit text-editing mode by c
l
ick
i
ng
the Commit Any Current Edits button in the options bar. If you select another
t
o
ol
while in text-editing mode, Photoshop prompts you to save your text c
hang
es
.
The Esc key can be used to apply text edits if the Use Esc key to commit
t
e
x
t
change is selected in the Type panel in the Photoshop preferences dialog box. The
reason this is a preference is that Esc is a standard shortcut for canceling an ac
tion
except for some applications, notably in Microsoft Office, where the Esc key is a
shortcut for exiting a field and committing e
dit
s
.
The first time a student presses the Esc key while editing text, an alert a
pp
e
ars
asking if
t
he
y
d
prefer using the Esc key to cancel text entry. While that alert is
supposed to come up only the first time, it may appear more than once while
u
si
ng
Classroom in a Book because Photoshop preferences are reset before each lesson.
Changing
the opacity and the mode of
a
layer
If students have trouble distinguishing the difference between opacity and
blend
i
ng
modes, you might want to explain that opacity simply controls the degree to whic
h
underlying layers are visible through a layer, while blending modes are
d
i
ff
eren
t
ways to combine the tone and color values of a layer with those of the layers
b
elo
w
it. Opacity is uniform, but different blending modes can alter contrast and hue
t
o
varying degrees across a layer, depending on the colors in a layer combined with
t
he
layers behind
it
.
You might want to ensure that students
understand
that both opacity and
blend
i
ng
mode are options not just for layers, but for layer effects and painting tools,
t
o
o.
Because of all the combinations, it can be confusing to determine exactly how
t
o
ADOBE PHOTOSHOP CLASSROOM IN A BOOK (2022 RELEASE)
29
apply or edit an image. Suggest that students apply blending modes and opacity
i
n
the following se
quenc
e:
Blending mode by
l
ayer
Opacity by
l
ayer
Blending mode by effect
Opacity by effect
Blending mode by
t
o
ol
Opacity by
t
o
ol
There are a few reasons for this suggested
order
:
Blending modes have a more
fundamental
effect on appearance, so should
b
e
adjusted e
ar
l
ier
.
Opacity lowers the intensity of an existing effect, so
it
s good to adjust
l
a
t
er
.
Layer blending
mode/opacity
and styles can be changed at any time;
adjusting
them first
do
e
sn
t
commit you.
Also, if applying opacity or a blending mode seems to have no effect, make sure
t
he
student has changed it in the correct location. For example, if opacity is changed
i
n
the options bar, that affects only the next time the current tool is used to paint. If
the
student intended to change the opacity of a selected layer, they should change
it
in the Layers
p
ane
l.
If a student
i
sn
t
sure which layer blending mode would work best, they can
take
advantage of the live preview capability for blending modes in the Layers
p
ane
l.
When the blending mode list in the Layers panel is open, mousing over the list
pr
e
–
views each item as the mouse passes over
it
.
F
la
tt
ening and
saving
files
Students must
understand
that once a file is flattened, there is no way to unflatten
it
(unless Undo is available). You can describe it as trying to unbake a cake into
it
s
original ingredients c
an
t
be done. This is why you should archive an
u
nfla
tt
ene
d
(layered) original of a file before flattening, in case you need to make changes
l
a
t
er
.
Make sure students are aware that many Adobe applications, including
A
dob
e
InDesign and Adobe After Effects, can import layered Photoshop files and even
preserve and work with individual Photoshop layers. For this reason, in many cases
flattening a Photoshop file is either unnecessary or may make the file less
u
s
ef
ul.
30
INSTRUCTOR
NO
TES
Using
the
Gradients
panel
The sidebar on page 97 is a brief overview of how the new Gradients panel
wor
ks
.
If you choose to have your students explore it further, here are some of the
mai
n
points to
em
pha
size:
Gradients are applied nondestructively, so that students can remove or e
dit
a gradient at any time. This is also a major advance over earlier versions of
P
hot
o
s
hop.
Depending on the layer type, a gradient might be applied as a layer effect,
a shape
fill,
or a fill layer. I
t
s possible to control how gradients are a
ppl
ie
d
by holding down a modifier key while dragging and dropping a
g
rad
ien
t
on a layer. For details, see:
h
tt
p
s
://he
lp
x
.adob
e.c
om/phot
o
s
hop/u
si
ng/
g
rad
ien
t
s
.h
tml#g
rad
ien
t
s
–
p
ane
l
What the Gradients panel actually does is store gradient presets. P
hot
o
s
hop
2020 and later use the same method of storing and applying presets for s
w
a
t
c
he
s
,
patterns, and shapes in the Swatches panel, Patterns panel, and Shapes
p
ane
l,
r
e
sp
ective
ly.
Gradient presets can be organized into groups
(f
olders).
You can find more gradient preset commands in the layer
men
u.
Exploring the
Gr
adien
t
edit
or
Gradients are a deep feature. You may want to extend the lesson by exploring
t
he
Gradient Editor, so that students
understand
how to make their own gradient
pr
e
–
se
t
s
:
Click the Create New Gradient button at the bottom of the Layers panel, e
dit
options in the Gradient Editor dialog box including the name, and click OK. The
new gradient preset appears at the end of the list in the Gradients panel. Try c
r
ea
t
–
ing different types of gradients, and customizing gradient stops in different ways.
I
t
s a good idea to make sure that students
understand
the difference
b
e
twe
en
Foreground To
Transparent
and Black, White gradients, both found in the Basics
group of the Layers panel.
Demonstrate
the difference between editing the color
and
editing the opacity of a gradient
st
op.
Using
layer comps
Challenge students to think of ways that layer comps provide a time-saving or
prac
–
tical advantage. You can invite students to create layer comps of this
file,
c
hang
i
ng
which layers are visible or which layer effects are applied in different c
omp
s
.
You may want to have students compare layer comps to layer groups. And
no
w
that Photoshop supports multiple artboards, you may have students compare
l
ayer
comps, layer groups, and artboards after students are
introduced
to artboards
i
n
ADOBE PHOTOSHOP CLASSROOM IN A BOOK (2022 RELEASE)
31
Lesson 13. All three are ways to organize a Photoshop document, but each
ha
s
advantages for different sc
enar
ios
.
Extra
Credit
sidebar: Creating a
pa
tt
ern
This sidebar gathers existing and recently added pattern creation features into a
single
wor
k
flow
:
The View > Pattern Preview command is new in the 2021 release of P
hot
o
s
hop.
The Pattern type of Fill Layer is not new, but the option to set the Angle of the fill
is new in the 2021 release of P
hot
o
s
hop.
The Patterns panel, which stores pattern presets, is not new. It was added as
par
t
of the overhaul of presets in the 2020 release of P
hot
o
s
hop.
The Edit > Define Pattern command is not
ne
w
.
Extra
Credit
sidebar:
Adobe
S
t
ock
This Extra Credit sidebar may present challenges related to using Adobe
S
t
o
ck
:
If your school or organization uses a Creative Cloud plan that does not
i
nc
lude
Adobe Stock, your class might discuss this sidebar without stepping through
it
.
Available Adobe Stock images may change over time or by region. You can
le
t
students know that they
don
t
have to use the exact ukulele image used in
t
he
book (Adobe Stock File ID #48738095); anything close enough will do. The
important
thing is that the image has a solid white
b
ac
kg
r
ou
nd.
If the Adobe Stock option is not available because the search field menu is
not
present, open a library first and then se
ar
c
h.
Students may get different search results if they enter
ukele
as the se
ar
c
h
term. The actual and correct spelling, shown in the book, is ukulele .
Supplementing the lesson
If your students are eager to learn more about layers, invite them to explore
t
he
options at the top of the Layers panel (the blending mode pop-up menu, layer
filt
er
–
ing, Opacity, Fill, and Lock options) and the commands on the Layer menu. If
t
he
y
enjoyed experimenting with the presets in the Gradients panel, encourage them
t
o
explore the presets in the similar Swatches panel and Patterns panel. The Sha
p
es
panel was also new in Photoshop 2020, and is covered in lesson 8.
32
INSTRUCTOR
NO
TES
Questions
The following questions are not in the
studen
t
s Classroom in a Book.
1
Wha
t
s the most versatile way to change the appearance of a layer?
2 How can you change the way in which layers combine visually?
3 How can you make a layer partially
transparen
t?
4 Suppose you have a selection border perfectly drawn around an area of the
i
mage
you want to work on, but discover that the wrong layer is active. What do you
do
now?
5 What are some examples of when
it
s useful that the shape of a selection
b
order
does not have to match the shape of the pixels on the current layer?
Answers
5 You might want a selection to be a different shape than the current layer
when