I sent this as a private message, but this is a good place to add it for anyone else who might be interested.
First off, thank you for your interest. Before I came along, there weren’t too many people looking at doing the Halo Wars style of armor. Bungie/343i didn’t really have a hand in it and it was kind of disowned. Personally, I love the look of the armor and will be doing it quite soon after doing my Spartan ODST armor.
Secondly, while I love the look of the Alessandro Baldasseroni Master Chief portrait, that’s not the style my armor files are. Don’t get me wrong, my armor and the one he made are both Halo Wars. However, the armor from his pictures is the concept, not the final product. The armor that my files are made out of, while highly similar to his concepts, is just a little off here and there.
With that said, there is no real template plan that I can give you regarding an undersuit. However, that doesn’t mean that you can’t make your own. Below, you will find the highest resolution pictures of the Halo Wars armors. You can use those as a jumping off point.
http://www.eklettica.com/pictures/Halowars/template.jpg
http://www.eklettica.com/pictures/Halowars/miniature.jpg
http://www.eklettica.com/pictures/Halowars/Halo_Character_Spartan_Render_01.jpg
http://www.eklettica.com/pictures/Halowars/Halo_Character_Spartan_Render_03.jpg
http://www.eklettica.com/pictures/Halowars/Halo_Character_Spartan_Render_02.jpg
http://www.eklettica.com/pictures/Halowars/Halo_Character_Spartan_Render_04.jpg
When you get your armor done, get a painting coverall (the cheap paper-like kind). Make sure it fits you snug, but not tight. Put it on and put your armor on over it.
Have someone draw around where your armor is using a sharpie. Take it off and compare it to the pictures in the link above. Draw in the “straps” and “plates” of the undersuit on the painter’s coverall. Make sure to overlap the armor some since you will be bending and moving a little. Now that everything is drawn in, label where everything goes and cut the painter’s coverall along the lines you just made. Congratulations, you just made a full body template.
I’d suggest finding ¼” foam matting and buying a roll. Cut out all the templates and such from the mat, and don’t forget the little holes and such through it, too. Line all the pieces up as they would fit on your body.
Now, you need to find (or make) a hexagon-shaped press in the right size. Make sure it is metal and it would help to be a little solid. Heat it up over a stove burner (not too hot) and press it into the foam to cause indentations in the proper shapes.
You will need some 1” nylon strap to attach it, as well as several push snaps. Attach the snaps to the strap and then hot glue the strap to the back of each piece. Because it’s only ¼” thick, you won’t have to heat-bend it at all.
Put a piece of tape over the snaps and plastidip/flex seal the whole thing in dark gray. Weather the edges and paint it up with whatever details you want on it. Don’t forget to black-wash the hexagons. You can use the hexagon press (with black paint) for a pair of dark gray leather gloves, too.
Put on your underarmor and line up the pieces. That will give you the placements for your snaps. Attach them, add a little rigging for your kit, and you are golden.