~ What is the difference between a "Graduated Skinner Blend" and a "Continuous Skinner Blend?"
The following side-by-side comparison has been created to show the difference between a Graduated Skinner Blend and a Continuous Skinner Blend:
I've started with 1 block of black and 1 block of white. I've divided each of the blocks in half.
I'll use 1 oz. of black and 1 oz. of white for the Graduated Skinner Blend, and 1 oz. of black and 1 oz. of white for the Continuous Skinner Blend.
I've conditioned and rolled out each of the blocks of clay on the thickest setting of the pasta machine. Then, I trimmed away the uneven edges.
Now I've placed the black sheets on top of the white sheets. (It doesn't matter which color you place on top. I chose black because it's easier to see.)
Now I've cut each stack. The way that I've cut the stacks will create the difference between the two blends. I've cut the Graduated stack to create 'offset' triangles; and I've cut the Continuous stack to create 'pointed' triangles.
Now, I've separated the layers and stacked black-on-black and white-on-white, then stuck them back together to form rectangles.
Next, I will pass these through the pasta machine, each in the same manner. (Pass through once on the thickest setting, then fold and pass, fold and pass, in the same direction, about 15-25 times)
I passed each blend through the pasta machine approximately 25 times...and now the blends look like this.
The Graduated Blend retains some solid black and solid white on either side; Whereas, the Continuous Blend does not. Rather, it fully blends from dark gray to light gray.
Here is another view with the blends turned sideways.
~ I realize that in the comparison pictures, the darkest ends of the fully blended sheets both look "black." However, upon close inspection (and in-person), the Graduated Skinner blend is solid black on its dark side, and the Continuous Skinner Blend is a very dark gray (almost black) on its dark side.
~ You may wonder why I have chosen to explain the differences between each blend. And you may wonder, "Isn't it enough to know how to make 1 type of Skinner Blend?" Well, perhaps. However, the subtle differences can make a great difference when you're trying to produce a specific effect. For example, below is a picture of two cane slices. The petals of the flower on the left were made from a Graduated Skinner Blend. The petals of the flower on the right were made from a Continuous Skinner Blend.
On the left, you can see the blend "graduate" from white-to-gray-to-black, whereas on the right, the blend flows "continuously" from dark-gray-to-light-gray.
So, it becomes a matter of preference, or a matter of basing what type of blend you want to make on the type of project that you have in mind.
~ When making Skinner Blends, you can "offset" the triangles a number of different ways to produce different effects. In the following diagram you can see some of the different effects that can be produced (This is a free-hand drawing, so please use your imagination to make up for my lack of drawing skills...).
A) You could only slightly offset them. This will produce a very narrow strip of solid color on each end with a large blend of color in the middle.
B) You could greatly offset them. This will produce a very wide strip of solid color on each end and a narrow blend of color in the middle.
C & D) You could combine the Graduated and Continuous techniques to form blends that have a solid strip of color on one side and blend continuously to the other side (C = solid white -> light gray -> dark gray; D = light gray -> dark gray -> solid black). However, with C & D, you will need to cut each color separately to form the desired shapes. Stacking the colors together and cutting will not work to produce the effects shown.
~ Judith Skinner introduced the "Skinner Blend." Her technique for making a Skinner Blend can be found here: http://members.aol.com/polyannie/shade.html (- webpage gone)
~ About terminology: To my knowledge, there is no comprehensive source for the terminology and vocabulary of polymer clay. As a result, I have come to call the different ways of cutting Skinner blends to produce different effects "Graduated" and "Continuous." I did this because, as a teacher, I needed an easy way to refer to the different ways of manipulating them. I found "Graduated" to be an easier way of saying, "truncated-triangle Skinner blend." And I found "Continuous" to be an easier way of saying, "non-truncated-triangle Skinner blend." However, regardless of what clayers have come to call them for the sake of clarity, and regardless of the different ways that clayers have come to manipulate them for the sake of variety, they are still "Skinner Blends." ~Thank you Judith!
*Update - Desiree McCrorey has published an instructional page on Skinner Blends which clearly illustrates how to achieve the different types of color gradients. It's thorough and easy-to-understand, so please check it out for even more information and insight on the Skinner Blend. ~Thank you Desiree!