slice (3rd left)
File > Export > Save for Web (legacy)

:: important
File > New > Document Type (Web)
View > Rulers
Window > Info (change to pixels)

:: guides
view > new guides (to key in position)
view > new guide layout (change preset to create quickly)

Change canvas color
choose foreground color, use paint bucket tool (under gradient)
add a layer under artboard 
use paint bucket tool to click on it

horizontal guides:
15, 22, 40, 64, 80, 220, 235, 300, 315, 380, 395, 410, 675, 690, 692, 706, 721, 738
768 - last one