For a long time, it was the baby boomers, born between 1945 and 1964, who commanded attention in the marketplace for their consumption preferences, habits and impact. Today, it’s the millennial generation, born between 1981 and 1995, that is the focus of numerous studies and marketing campaigns. It isn’t just their youth and buying power that is propelling this group’s influence: the U.S. Census Bureau projects that millennials will overtake boomers in population in 2019.

A number of studies have highlighted the ways in which millennials are changing the market, including the market for packaged foods like bakery and snack products. When it comes to packaging, millennials comprise a large segment of the population that is driving a greater emphasis and change in sustainable materials and recyclability: according to a recent report by The Shelton Group, 70% of millennials said a company’s environmental focus affects their purchasing decisions and believe that large companies and brands, in particular, can have a positive impact.

Members of the millennial generation also helped develop and use technologies that have led to the priority of customization in the marketplace. As a “Marketing to Millennials” report from research firm Mintel shows, this demographic group is interested in personalized packaging, including limited-time packaging, that allows for a unique purchase experience. Millennials are likewise a force in e-commerce: the “2017 U.S. Shopper Trends Report” from the Food Marketing Institute shows that the frequency of online-only buying rose from 28% in 2016 to 43% in 2017, due in large part to millennial consumers.

As tempting as it might be to lump young consumers together, there are some significant differences between millennials and the group behind them, Gen Z. For example, a study from the National Retail Federation and IBM shows that “almost all” members of Generation Z (born between 1995 and 2012) prefer to shop in brick-and-mortar stores, and differ from older generations in that they appreciate and use technology while also enjoying the hands-on experience of browsing buying things on a store shelf or case, underscoring the importance of eye-catching package design. Manufacturers and retailers can also take note that Gen Z consumers are more likely to eat fresh, home-cooked meals than the generation before them, according to a “Future of Eating” report conducted by research firm NPD.

While boomers, millennials and Gen Z members are the focus of research, marketing and product development, those in other (and often overlooked) generations have their own unique preferences and behaviors. According to a report from Acosta, members of Gen X (born after 1964 and before 1981) said they spend the most per month on groceries compared to other age groups, and 60% said they regularly look for new items in a store.  Gen X consumers also appreciate convenience, with features like multi-serving packages and packages with recloseability.

Older shoppers, including those in the Silent Generation and the older baby boomers, tend to be in smaller households and typically look for smaller package sizes. According to research from Chicago-based research firm I.R.I., food companies are looking to offer easier to open packages for senior buyers.