While printing presses were in use throughout Song China, you have to account for the extremely low literacy rates that is typical of this time period. There are very few sources but if I remember correctly most scholars place the literacy rate during the Song era around 10-30% of the total population. While great written works definitely did exist, Chinese storytelling at the time was mostly oral or music based as well. These two factors meant that 'low-brow' reading material didn't really exist in Song China as paper was mostly used as a tool of the bureacracy, rather than as a form for entertainment.

The rise of cheap pulp fiction like penny dreadfuls can be linked with the emerge of a middle class, a social strata that only became prominent in the period of industrialization. This is because a multitude of factors - namely rising real wages and widespread literacy which gave the middle class disposable income to spend on cheap manufactured goods. Thus it was only in 19th century Europe that we began to see literature begin to contest traditional forms of 'low-brow' entertainment such as commedia del arte and song/dance.

Essentially, 'low-brow' reading material didn't fully exist due to the extremely low literacy rates and the dominance of music and oral tradition as forms of 'low-brow' storytelling. That means a lack of demand - and disposable income - for literature that wasn't cheaply mass produced.

Disclaimer: I know art history far more than I do literature.

Others might have a better answer than I do, but to sort-of offer an explanation, there were already a number of pre-existing manuscripts on a wide variety of subjects that made their way, via popularity, to being printed. It could be anything from holy or devotional works to famous stories (the romance of the rose, various histories, and hunting manuals, for example), to playing cards or artistic prints.

Really though, mass consumption is a tricky term. Literacy rates were not particularly high, even with an increase in print technology. I think the greatest example (in the west) of early rising literacy rates would be during the golden age of the Dutch Republic- they had a growing middle class during that time. That's probably where you might find the earliest examples of what you're looking for, but I personally couldn't tell you of anything particularly pulpy or low-brow in terms of literature. [for info. on class distinctions, .ect there's Simon Schama, the Embarassment of Riches, and a book titled The Public and Private in the Dutch Golden Age... I'm sure there's more on the topic out there as well.]

You should, however, take a look at Dutch genre paintings (as well as some of other similar subjects) by Dutch artists such as David Vinkboons, Frans Hals, and Pieter Bruegel (just to name a few). There's a large amount of these paintings, all centered on characters, bawdy scenes, and/or peasants. [Historian Wayne Franits writes a good book on the subject of genre paintings]

Edit: Thought I should note that I mention genre paintings primarily because they were often made into prints (along with other subjects). Although the subjects and prints of these images might not qualify under today's understanding of "mass consumption," they were cheaper than commissioned portraits and history paintings. Not only were they cheaper, but considered relatively lower-brow, to put it in modern terms. Karel Van Mander describes a hierarchy of painting and artistic subjects at length, and was partially responsible for the shift from prints to paintings in the oeuvre of Hendrick Goltzius.

In the really-early days of print, speaking for the West, paper was still too expensive to allow paperback pulp fiction type books. However, pamphlets floated around pretty much since the beginning of the printing press. In James Burke's The Day The Universe Changed, ep 4, at 34:50, here he goes into some detail about a pamphlet written by German Protestants against the (Catholic) Church. It has text in Latin and German underneath a large color illustration of the pope getting mooned by some cheeky peasants, who, to put it gently, have a lot of cabbage in their diet.

This would be their equivalent of one of our cable news rants by Sean Hannity or Ed Shultz. Every middling, urban Johann Q. Shopkeeper would enjoy, or have his intelligence insulted by these.

I'm no expert, but as far as I know there was a considerable printing industry in the Low Countries during the eighty years war (1568-1648). Most books had a religious aspect to it and printing was used heavily in the propaganda of both protestants and Catholics. Holy lives of saints, books with prayers, etc. were printed in pocket sizes. Nevertheless there were also books concerned with more mundane topics. Popular genres were guides for etiquette and good manners, and cookbooks also came into fashion. Literacy grew during the religious wars because both sides tried to influence as many people as possible and education was one aspect of the propaganda war. The Jesuits founded many schools and colleges during the 17th century and religious education in parishes was taken up more seriously than before. Literacy still remained quite low, but a small number of people from the lower classes (artisans, shopkeepers,…) could certainly read and had access to relatively cheap book(let)s.