"One word: Plastics."

That famous line from The Graduate constituted career advice in 1967. Some 50 years or so later, the plastics industry has matured a great deal. But it's now so intertwined in society that there's still a good reason to watch the plastics space. Here are three companies worth a look: Bemis Company (NYSE:BMS), West Pharmaceutical Services (NYSE:WST), and A. Shulman (NASDAQ:SHLM).

The things you use every day
When it comes to plastics, you use the substance so often you may not even realize it. And that's where Bemis comes in. Bemis makes rigid and flexible plastic packaging. About two-thirds of its revenues come from the United States, with the rest spread across the world.

You've probably seen or used its products. For example, the company makes such things as single-serve plastic pudding cups and single-serve squeezable applesauce pouches. And while its big businesses is with food packaging (a far more diverse industry than you probably realize), it also serves the healthcare sector.

One of the key factors driving the company's future will be the shift from rigid packaging such as glass bottles and cardboard boxes to flexible packaging made of plastic. The applesauce packet is an example, but so, too, are diapers, frozen foods, and soup. It's a broad-based and global shift that fits right into Bemis' wheelhouse.

That said, the packaging company has been working to increase its profitability. It's homing in on its best investment options to improve return on invested capital and working on its operations to increase profit margins. The goal is to drive revenue growth of around 6% equally through internal and external (i.e., acquisition) avenues. That's a decided turn from recent history, when growth came disproportionately from inorganic means. That's a solid goal and makes this plastic packaging maker a worthy consideration for investors.

Drugs, or what they come in
Another unique plastic company is West Pharmaceuticals. At first you might think it's a drug company, but instead it makes the products in which drugs are distributed and delivered. The best example is probably plastic syringes, but it makes far more than that. And it serves drug companies around the world.

The main categories it serves include vials, syringes, and so-called delivery systems. the best way to visualize this delivery systems is devices that use cartridges. These businesses are expected to grow as much as 5%, 6%, and 10%, respectively, over the next few years. That should help keep the company's top line growing in the near term.

However, if you have a long-term view of the world, West could be an interesting play on the aging baby boom generation. As nations try to contain healthcare costs, patients will be kept out of medical facilities. How? Through the use of medicines and drug delivery systems that can be used at home. West is likely to be a big part of that.

The building blocks of plastic. Source: Rohini, via Wikimedia Commons.

The basics ...
A. Shulman is further back in the plastics food chain, providing the resins that others use to make plastic items. The ultimate end markets its products reach include the packaging, automotive, construction, and electronic industries, among others.

In recent years, acquisitions have played a big part in Shulman's plans to expand its business. The deal to buy competitor Citadel is a good example. On its own, Shulman's U.S. and Canadian revenue represented around 23% of the top line, but with Citadel that's expected to reach 34%. That helps to even out the company's global footprint.

Basically, Shulman is using deals to expand its reach, increase its product portfolio, and create business synergies. All good things. Look for acquisitions to continue at this plastics player. That said, from an investor standpoint, if you're watching plastics, this is probably the purest play of the three companies here.

Ubiquitous, but someone's making it
Plastics are all around us. Key areas where you're likely to see it show up are in packaging, which is Bemis' specialty, and medical care, which is what West Pharmaceutical does. The success of these companies will come from providing ever more complicated plastic items to the world. That said, if you're watching the plastics industry and you want to get back to basics, A. Shulman may be the best option, since it provides the building blocks others use to make plastic products.

Reuben Brewer has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.