Sight size - what is it and why do we use it?

Sight size is, in short, drawing things exactly the size that you see them. Yes, that's it.

As a method of learning, sight size is a clear objective language through which the student and the teacher can create a direct, clear language, free of theoretical labyrinths and subjectivity. This objectivity is an incredibly useful tool to make critiques rich and helpful.

Both, (master and student) see the exact same thing, and through the tools used to measure, they can solve the puzzle at hand with outstanding accuracy.

Part of the purpose of training in art is becoming more apt in your ability to see shapes, proportions, relationships, etc, and sight size is an amazing way to speed up this process. It allows you to tap into a rhythm of observation and reaction to nature that no other method can offer, without the confusing subjectivity of off-scale comparison or the need to second guess the impression of reality and it's composition.

Many artists through history, like Antonio Mancini and John Singer Sargent, have used sight size as a method of learning, as well as to approach their professional work.