Gently roll out the dough until it reaches 20 x 110 cm. Place it in the fridge if the dough resists too much while rolling. A 20 min rest in the fridge will let the gluten relax.
Lift the dough and it will become a little bit smaller in length, but you should still have 100 cm of dough length to work with.
Place the dough on a cutting board, and on the top of the dough, mark 12.5 cm all the way along the dough.
Along the bottom of the dough, begin by marking 6.25 cm, then continue marking 12.5 cm.
Cut the dough diagonally to create triangles for your croissants.
For each triangle, on the end opposite the point of the triangle is a flat piece. Cut the middle of the flat piece ~ 1.5 cm into the dough.
Gently pull the dough to make it a bit longer. It's easiest if you use your hands to gently make the dough longer to roll.
Place the dough on the counter, and start with the flat piece, roll the dough onto itself and place the tip of the triangle down. Place the rolled croissant on the baking sheet. Repeat until all of the croissants are arranged on their baking sheets.
Using the egg wash, brush the egg/water mixture onto the croissants. Make sure you cover every surface of the croissant, as this prevents the dough from drying out. Let the dough proof for ~2 hours. It should be in a room that's about 24-26 degrees C.
When you're ready to bake your croissants, give them another egg wash, right before putting them in the oven.
Bake the croissants at 410 degrees F for 7 min, then turn down the oven to 375 degrees F for 13 minutes.
Let the croissants cool on a wire rack until they are room temperature.