Wednesday, December 23, 2015

Unit I, Lesson 6--Cadmium Lemon Color Chart


Completed Cadmium Lemon Color Chart
Cadmium Lemon is an opaque yellow that leans slightly green (so there's a bit of blue in it).  Fair warning, this is a L O N G blog post.

Materials needed:
  • Oil Colors
    • Alizarin Permanent
    • Cadmium Red Deep 
    • Transparent Oxide Red
    • Cadmium Yellow Light 
    • Cadmium Lemon (lots of it)
    • Viridian Green
    • Phthalo Blue
    • Ultramarine Blue
    • Titanium Zinc White
  • Canvas pad--I used Centurion oil-primed linen, 9"x12"
  • Masking tape--I used 3/4" tape
Unit I, Lesson 6 took me about 2.5 hours to complete.  It took longer because I was more conscientious about the value steps, as outlined below.

Step One: Divide the canvas

Divide your canvas pad using the method outlined in Unit I, Lesson 1.  See my time-saving T-square trick here.

Step Two:  Arrange the colors

The colors remain in the same order as in the first color chart.

Step Three:  Mix the colors and apply the paint

As with the prior lessons, the object of this exercise is to use the top row to display the pure paint, without any white, mixed in the same order.  Then, for each column, tint the rows lighter in even steps.  Because this color chart is a reference for Cadmium Lemon, the first column consists of only that hue.  The second column consists of Cadmium Lemon + Viridian Green, the next color in my palette.  The third column is Cadmium Lemon + Phthalo Blue, then Cadmium Lemon + Ultramarine, Cadmium Lemon + Alizarin Permanent, Cadmium Lemon + Cadmium Red Deep, Cadmium Lemon + Transparent Oxide Red, and finally Cadmium Lemon + Cadmium Yellow Light.

As I alluded to in the last lesson (here), I figured out a way to check and correct the value steps between the top row (the darkest or lowest in value) and the bottom row (the lightest or highest in value).

Value Exercise

Here is my value scale, next to some pools of paint on my glass palette.  As you can see, my value scale is well used and covered with paint and thumbprints.  You can buy a nicer looking new one here.

My value scale 
The value scale is a simple card-stock gray tone scale that lists in order ten value levels from the darkest or lowest (nearly black, at Value 1) to the lightest or highest (nearly white, at Value 10).  The darkest or lowest value possible for each pure color or combined colors is the pure paint or mixed combination without any added white.  The lightest or highest value for each pure color or combined colors is the hue tinted with enough white to match Value 10 or higher on the value scale.  

The first step in standardizing the steps between values in each column is to find the step on the value scale of the pure color or combined color.  It is very helpful here to take a picture of the paint next to your value finder (make sure you aren't casting a shadow) and edit the photo to turn it gray.  Here is an example:

Cadmium Lemon and value scale
You can squint to see the value compared to the value chart, but editing a photo makes it very clear where the value falls.  This works because it removes all color saturation, which can confuse the value issue.  Here's a black and white image of the same image:

Cadmium Lemon and value scale, black and white
Looking at the black and white photograph, it is clear that the value of the pure hue is slightly darker than Value 9 and slightly lighter than Value 8.  Now I have found the value of the top row of the column.  Keeping in mind that the last row should always match Value 10, I have the information necessary to create equal steps in value.  The top row of Cadmium Lemon ranges from Value 8-9 and the bottom row should be Value 10, as shown below.

Cadmium Lemon, bottom row, Value 10
Cadmium Lemon, bottom row, Value 10, black and white
The middle row should fall somewhat equally between the two, at Value 9-10.  Because at full saturation yellows start out high in value, the steps between the top and middle and middle and bottom rows are subtle, and they do not necessarily consist of separate numbered steps on the value scale.

The steps become more obvious when introducing colors that are lower in value at their most saturated, including greens and blues.  So, adding Viridian Green to Cadmium Lemon for the second column resulted in a lower starting value, as you can see in this image.  Remember that pure Cadmium Lemon at full saturation is about Value 8-9.  Here, it is obviously much lower.

Cadmium Lemon + Viridian Green
Here is a photo showing where the top row actually falls on the value scale (Value 4-5).

Cadmium Lemon + Viridian Green (black and white)

Cadmium Lemon + Viridian Green (black and white)
Knowing that the highest value in the column must be Value 10, the middle row must fall between Value 4-5 and Value 10.  The closest to the middle of these two values is Value 6-7.

Here is my first try.

Cadmium Lemon + Viridian Green + Titanium Zinc White

When I took a black and white photograph of the same image, it was too light, falling right at Value 7.

Cadmium Lemon + Viridian Green + Titanium Zinc White; too light at Value 7
So, I added more of the Cadmium Lemon + Viridian Green mixture to lower the tone.  Here is the corrected middle value:

Cadmium Lemon + Viridian Green
And, in black and white to confirm:

Cadmium Lemon + Viridan Green + Titanium Zinc White; Value 6-7
So, in the Cadmium Lemon + Viridian Green column, we know the top row is Value 4-5, the middle row is Value 6-7, and the bottom row will be Value 10.  So, the second row should be around Value 5-6, and the fourth row should be around Value 8-9.  Not exactly perfectly equal, but very close.  I continued this process with Cadmium Lemon + Phthalo Blue, and there you can see that the top row begins even lower in value.

Column 1--Cadmium Lemon; column 2--Cadmium Lemon + Viridian Green; column 3--Cadmium Lemon + Phthalo Blue
Therefore, there is more "space" between the steps on the value scale, which you can see when I turn this photo black and white.  With the darker colors, I found I have a tendency to not create enough "space" between the fully saturated hue (the darkest value) and the next row.  Using the value checker created more even steps.

Cadmium Lemon Color Chart in progress with value scale, black and white
Step Four: Remove the tape

Cadmium Lemon Color Chart in progress
Step Five:  Let it dry


Completed Cadmium Lemon Color Chart.  Columns, left to right:  Cadmium Lemon; Cadmium Lemon + Viridian Green; Cadmium Lemon + Phthalo Blue; Cadmium Lemon + Ultramarine Blue; Cadmium Lemon + Alizarin Permanent; Cadmium Lemon + Cadmium Red Deep; Cadmium Lemon + Transparent Oxide Red; Cadmium Lemon + Cadmium Yellow Light
You can also use the value scale to confirm you are adding equal amounts of a high value hue (yellow) with a lower value hue (blue, green, or red).  You can find the starting value of each with the value scale, and the combined hue should fall in the middle of the two starting values.

Looking at the finished product, you can definitely see that the steps beginning lower in value are more even than in my previous charts.  Isn't it pretty?  Let me know in the comments what you think of this exercise!

You can access all of the lessons in this unit from the Index of Lessons page here.

Upcoming Lesson  

Unit I, Lesson 7--Viridian Green Color Chart

Materials needed:
  • Oil Colors
    • Alizarin Permanent
    • Cadmium Red Deep 
    • Transparent Oxide Red
    • Cadmium Yellow Light 
    • Cadmium Lemon 
    • Viridian Green (lots of it)
    • Phthalo Blue
    • Ultramarine Blue
    • Titanium Zinc White
  • Canvas pad--I used Centurion oil-primed linen, 9"x12"
  • Masking tape--I used 3/4" tape
Unit I, Lesson 7 took me about 2.5 hours to complete.
    
As always, please subscribe to follow along or join in.  I'd love to meet you--please introduce yourself in the comments.  Also, your feedback is most appreciated.  Leave your questions, comments, and hate mail below.  (I won't post the hate mail, ha!)  Thanks for stopping by.  Monique

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