Took 3 hours in the end, but I did stop my mining for the last half hour to speed things up a bit.
After that baking my model now looks like this:
Now it's time to add a few materials. Substance Painter works the same sort of way that Photoshop does, using layers, opacity/transparency and blending modes. You grab materials from the Shelf and drag them into the Layers tab. Layers at the bottom appear below layers at the top.
There are also Smart Materials which are basically Materials with multiple layers and effects saved as a collection with a Smart Material name. I'm going to create a Smart Material specifically for my Storage Crates because I have 3 different types of crate and I want them to share the same bunch of materials and effects, with cosmetic changes changes made to make them look different by altering different attributes for some of the Materials in the Smart Material. Hope that makes sense!
To start off with I want a Painted Steel Material (there's also a Painted Steel Smart Material but I'm not going to use that). So I go to the Shelf, click on Materials to see the different Materials that are available to use, select Painted Steel and drag it onto the Layers. Hovering over the Material lets you see a larger image than the one used for the icon so that you can see more closely what you're getting as you can see in the pic below:
Once you drag and drop the Material onto the Layers tab the model fills up with that Material as shown in the next pic. Each of these Materials also have Parameters that you can change, also highlighted in the pic. For this Material I'm going to change the Base Colour parameter and the Rust parameter:
I've changed the Paint Colour to green and added some rust:
Looks a lot better so far but it's not quite the look I want to be going for. The Nakamura Mining Corporation was founded and ran by Shinji Nakamura who died mysteriously at the age of 93, following his death his son, Koto Nakamura, took over the company and has managed to run it almost to the ground. So I'm going to want these crates to look a bit more weathered than just a bit of rust. I want to have wear and tear on the edges of this model. Luckily there's a material and generator made for the job - the Steel Rust And Wear Material and the Generator called Metal Edge Wear.
When I drag the Steel Rust And Wear Material and place it on top of the Painted Steel Material it changes the look of my model completely, and not in the way I want. It looks entirely Steel Rust And Wear coloured, with the rust of the Painted Steel layer showing underneath. What I want is to see the Painted Steel layer underneath and have the Metal Edge Wear showing where the metal has worn.
You can get around this by adding a mask. A white mask will have the layer opaque, a black layer will have the layer transparent. So if you paint on a white layer with a black brush you'll see the layer underneath and if you paint a black layer with white paint you'll show the current layer you're on.