You don't need a printer, online only is fully acceptable.

However, what you do need is an "impact rating" calculated by Web of Science(TM). That rating is based on the number of citations articles in your journal gets from other rated journals.

Since your journal is new, it won't have an impact rating, meaning scientists won't publish in it, meaning you won't get an impact rating.

But the alternatives exists, e.g. Bentham and Hindawi are both running spamtastic marketing campaigns for 100s of open access journals, most with none or negligible impact ratings.

There are good and successful ones too. PLoS have very high quality open access journals. Expensive, though.