Brushing on the egg wash with a pastry brush.

Bread glazes, such as egg wash, are best applied with a pastry brush before the dough has reached 80 or 90 percent of its rise and again after baking. Some can be applied before rising and again, before baking. Make sure you do not “seal” the bread dough to the pan with it so it can rise freely.

After glazing, slash your bread dough with a baker's tool called a lame, so there is a more dramatic contrast between the interior and the exterior of the bread. Do this on ALMOST risen dough (so apply your glaze, in this case, right before when the dough has ALMOST risen). Then, apply an seeds or toppings, if using. Place the dough into a hot oven to bake.

This how to baking technique is used with the:
Stromboli Recipe Tutorial

HOW TO TIPS:
1. Beat 1 large egg and 1 tablespoon water together with fork to combine. This makes an egg wash.

2. Remove the towels from the stromboli and brush the risen dough with the egg wash. Then, if applicable, slash or score the bread dough.