Editing 1d4chan's Assembling, Painting and Basing Guide (section)

===Non-Plastic Modeling Tips===
Perhaps you're working with one of the many alternatives to plastic for models- metal was quite common back in the day, and resin was a common stop-gap between metal and plastic for many miniature businesses- including Games Workshop, who still has the Firstborn Techmarines, Commissars, and Pyrovores solely in finecast (the trade name for their specific resin blend). There are pros and cons to each.

Metal is much heavier, and more difficult to assemble for models without pinning- best seen by the old metal models of Abaddon the despoiler, whose arms dropped off so often it became a meme. They also have more chance of losing paint over time, and are usually more expensive- both from actual cost of metal being higher than plastic and the gradual decrease of metal miniatures being produced since the 90s. That being said, it's far from fragile, and will last you quite a while; they also usually have more defined features than plastic, which means a higher maximum quality.

Resin tends to bow in the other direction- light, cheaper to produce, easier to assemble, and keeps paint well, but easy to break and can melt in high temperatures, much more often than plastic. The cheaper/inferior quality types (particular the finecast by Games Workshop) tend to have bubbles and warps straight out of the box, and while these can often be exchanged/refunded, it's still a great waste of time. These can be mitigated with Green Stuff.