This episode of Forge Webs™ is brought to you by GLASS.
Yes, that wonderful material that provides beautiful light to shine through your walls. That wonderful material that provides you with a instant weapon in times of stress and/or danger. That wonderful material that keeps you safe as you look out onto the battlefield.

Glass is a wonderful material isn't it? It has so many uses in Forge. There's just one problem with it. Well, actually there are two. Okay, three. Lets go through them one by one, shall we?

Lag
This is something we remember from Halo Reach. The more glass you have, the more lag you experience. Glass catches light and allows it through at the same time. It also allows players to see though it while providing a barrier at the same time. In Reach, a lot of the Forge items had glass in it. Even if it was a small 1x3 block, there would be glass used as decoration on it. In Halo4 we don't have that problem. The glass has been limited to a few items. I believe it's also why the Window Coliseum has been moved to the Buildings category on Forge Island. If it cost more, the less you're going to use it, thus causing less lag in maps.

Not Solid
Just as in Reach, items like the Glass Canopy (may not be called that) under the Decoration menu and the Double Window in the Walls menu is so thin that players can close enough to them and shoot players/items on the other side. Like all Forge objects, they have a hit boxes to prevent this. But there are certain areas of the objects that allow players to shoot through them. I'll not point these areas out because I don't want to risk them being exploited. It's best to use these items as simply windows. Place them in areas of your map where it will mot matter of players shoot through them. Or place them as a light source for your bases.

Light
I've noticed a issue with windows on Forge Island that I've not noticed on other maps. Dynamic Lighting does not seem to effect them at all. On maps like Impact, shadows effect the transparency and shading of glass. But on Forge Island, this does not seem to be the case. However, light still passes through glass on Forge Island. To test this, I've created a simple closed column. The play area inside this column is still very bright. What more, the glass is less transparent and just as bright as it would be if there were no walls.

In the images below, we see a yellow light and a grav lift added to see if they have any effect on the glass. The result? None what so ever. The color of the light did not matter either. This is something to keep in mind when attempting to build dark maps on Forge island. Class can literally be used as a light source to direct players.