I’ve personally never used bread flour to bake bread. I always use all-purpose flour because that’s what I always have on hand. And I’ve had great success with it. So if you don’t have bread flour, no worries. You can use all-purpose flour and make very tasty bread out of it. I did read that the higher percentage of gluten in bread flour (somewhere between 11-14%) makes it ideal for bread because it makes the dough more elastic and easier to work, resulting to lighter textured breads. So if you’re curious, you can substitute all-purpose flour for bread flour easily. It’s a 1:1 substitution. You can read all about it and the different kinds of flour here. A quick note that not all all-purpose flours are the same though. For example, the all-purpose flour we get here in Canada is higher in protein than the equivalent product in the US. So, when milled and used to bake bread, Canadian flour can “feel stronger and more elastic than an equivalent American flour, which will feel softer.” Our little factoid of the day and something to keep in mind.