i4 Custom Paint Tutorial
I read a couple of threads, where people were asking "how to" for doing custom paint jobs to their i4's. No one really had a good in depth answer.
I saw a picture of a mask and I wanted to do the same to mine. Here I'm going to do my best to put a tutorial together of how I did it.
Suplies
Paint. I used Krylon Fusion Paint. It is made for plastics. The paint has a chemical reaction where it fuses to the plastic. You do not need to do any preparation to the area you are painting prior to. Krylon paint can be purchased at Wal-Mart. I also seem to see it at a lot of your mom and pop type hardware stores.
Painters Tape. I used Scotch Blue Painters tape.
Razor.
Vaseline & Qtip.
Rubbing Alcohol & Cotton Balls
Double Sided Adhesive Tape. I used tape of a 1mil thickness. The tape can be purchased at Grainger.com I used a brand called 3M.
Per Jsmoke718, DYE uses Loctite 380 Black Max to secure the foam to the mask. If anyone uses this post how it worked out for you. I'm curious to know.
Preparation
First things you will want to do is remove your lens and soft ears/strap. If you are unsure on how to do this refer back to your manual.
Take your tape of choice and tape over what ever you do not want to paint. In my case I only wanted to paint the lens frame, so I covered the bottom half. To make taping easier, I found its best to use an excess amount of tape then use the razor blade to trim it back to make your lines tighter.
If you are meticulous about little detail, don't frustrate yourself with cutting little pieces of tape to cover small areas. That is what the Vaseline is for, but this will be done last.
If you want to spend the time trying to tape up the foam on the inside of the mask, go for it. I decided to slowly peel it back. It held together very nicely and is reusable.

Start from one side and gently start to pull it back. Don't pull it by the soft parts of the spongy foam. Instead try to pinch it at the base (where the hard piece of foam is attached to the adhesive) and pull it from there.

Take your time and it will stay intact and not come off in pieces. This will allow you to reuse it.

Here the foam is completely off. Some adhesive stayed attached to the mask, and pulled some of the base foam off. No biggie. Just take your fingers and pull this off and throw it out.

The adhesive that didn't stick to the mask is still on the foam, you want to take this off. Very gently peel the adhesive back off the foam. A very thin layer of foam will come off with the adhesive. No worries, it will not affect the foam.

This is what the adhesive looks like with the thin layer of foam coming off as well.

Once you finished your foam will actually look like a brand new piece.
The reason I did this instead of taping is because A) taping up the foam would have been time consuming and could possibly have ruined the foam when you tried to take the tape off and B) this will allow you to cover more surface area when painting.

On the inside of the mask were some black areas that I didn't want to paint. Instead of cutting small pieces of tape to cover these small areas I used Vaseline.
Take your Vaseline and a Q-Tip. Scoop up some Vaseline and spread a layer on the areas you do not want to be touched by paint. Once you are done painting wipe the Vaseline away and it will still be the original color.
Because you used the Vaseline you may have gotten small traces on the area you want to paint. To ensure the area being painted does get painted, take your cotton swab and shake some Alcohol on it. Wipe the area you want to paint to remove any Vaseline, and to just give a general wipe down before painting.
Painting
Pending on the paint you choose to use follow those directions. I used Krylon, so I can only speak on behalf of what I've used.
Shake up your paint 1-2minutes. I held the can back about 6-8 inches and did short bursts of paint in short sweeps. I would then give the paint 5-10 minutes to sit, then do it again. Pending on the darkness of the color you chose will determine how many coats you do. Over the course of one hour I probably did a total of 3-4 coats.
I then let the paint dry for 2 hours before doing Blood Splatter.
By the way! If using Krylon, and you're doing more than one coat you
HAVE to do it before 24hrs or after 7days. Because in between this time the paint begins to fuse and the additional wet paint can ruin that fusing process.

Before Painting

First Coat

Final White Coat
Next I did a blood splatter effect. For this all I did was spray the paint into a cup, to cause the paint to pool, then I took a brush (or you can use a tooth brush) and dipped it into the cup. Now just sling it at your mask, distance and amount of paint is up to you. I practiced on paper before doing it on the mask.

This is what the mask looks like after painting.
Let your mask dry over night before taking the tape off, wiping off Vaseline, and sticking the foam back on.
Completing
Your mask is done drying.
Remove all the tape, and just take a paper towel and wipe the areas that you placed Vaseline. You may need to use your finger nail to flake the Vaseline off, as the layer of paint above the Vaseline did dry. Just know what is Vaseline and what is the area you intentionally painted.

Take your foam and measure up where you want it to go, this should be easy. Take your double sided adhesive tape and place along your foam, I ran the tape along and off the edges of the foam and trimmed it back with a X-acting knife. Remove the wax paper off the other side and place it back on your mask. Easy as that. Press and hold it against the mask so you know its secure. Your done.
Finished
The paint takes a full 7 days before its done fusing. I would wait till then to put your lens and strap back on. Just to insure nothing gets chipped or messed up. Definitely DO NOT play with the mask until the 7 days are up.
If you allow for the paint to complete the fusion process for the allotted seven days, the paint should hold fine against direct hits.
I play more woodsball than speedball. I was out in the woods walking through briers, the paint did not sustain a single scratch (although my brand new lens did). I received three shots directly on the frame and the paint didn't chip. The paint is solid, and very durable.
This is just a general tutorial. I'm not a very creative person so I copied a design I liked. I'm sure many of you can do some awesome designs and color schemes to your mask. If you do customize your mask using this tutorial post a picture here so I and others can see your work. You can also probably use this tut on any other kind of mask as well. Hope this helps.