What indicates that dough is easy to stretch?

The indication that dough is easy to stretch is when it has doubled in size. This is a result of fermentation and the development of gluten within the dough. As yeast ferments, it produces gases that cause the dough to rise, leading to the formation of bubbles. These bubbles create a network of gluten that provides elasticity and extensibility to the dough, making it much easier to stretch without tearing.

In contrast, dough that is firm to the touch or hard and crackly lacks this necessary gluten development and elasticity. Cold and sticky dough may also indicate that it hasn't had sufficient time to develop and relax, which is essential for stretching. Therefore, the dough that has doubled in size shows that it is well-proofed and ready to be shaped, highlighting its capacity to stretch easily.