A couple of months ago I published a rules-light generic RPG called Tricube Tales, which used DTRPG's phone PDF size (2.25" x 4"). It's a convenient format for smartphone users, but some people really dislike reading on their phone or using electronic devices at the table, so I thought I'd see if I could create a print-on-demand version as well (if you've not read my earlier blog posts about print-on-demand, you can read them here, here and here).
The problem was, I didn't want to redo all the layout work -- but I also didn't want massive text, so I needed a very small book size. Unfortunately, the smallest size DTRPG currently offer is 5" x 8", which was a bit too large (and they don't offer it in premium either).
However, I noticed that Lulu offer a 4.25" by 6.88" pocketbook size, so I decided to try that out. I started with a copy of my phone PDF, added margins to increase it to 3.09" x 5", then repositioned the frames and added higher resolution (600 DPI) versions of the images. I also added a vector image around the page numbers so that I could push the frames up the page, otherwise, the margins at the top and bottom of the pages looked very big and empty.
I then used docuPub to resize the entire PDF to 4.25" x 6.88", which is around a 1.375 times size increase (this was also why I used such high-resolution images). As my phone PDF uses a size 8 font for the body text, the enlarged text in the printed book is pretty comfortable to read.
For some reason, I couldn't get Lulu to accept the PDF with bleed (I've had no trouble with other book sizes, but it repeatedly refused the pocketbook size). In the end, I gave up, as Tricube Tales only has a fairly light page background anyway, and I didn't think it would make much difference. In retrospect, I think the clean white background is probably better for a physical book than the slightly off-color white I used in the smartphone version.
The standard paperback costs $2.21 for black and white, and $3.22 for color. The premium paperback costs $2.50 for black and white, and $6.34 for color. That's for a 47-page pocketbook (the book needed to be at least 48 pages, and the last page needed to be left blank). Shipping is normally pretty expensive, but Lulu often have special offers, and I was able to get a 15% discount plus free shipping.
My order was split into two, and I'm still waiting for the premium books, but I've already got a pretty good idea of what they'll be like (as I've ordered premium books through Lulu in the past). The photos I've posted here are from the standard black and white, and standard color.
The last image is from the black and white version. It looks fairly decent, but some of the artwork doesn't work so well in grayscale (it comes out quite dark). I definitely prefer the color version. EDIT: Setting the output to "greyscale" in Scribus generates a greyscale PDF, and this looks much better when printed. So don't upload color PDFs to Lulu if you want to print them in black & white!
EDIT (28-Jan-2020): The premium proofs arrived yesterday, and I was a bit disappointed. I thought the thicker paper was much nicer for SotGH, but that was 8.5"x11" (US Letter), while Tricube Tales is just 4.25"x6.88" (pocketbook). The premium paper makes it quite difficult to flick through the pages of such a small book. Furthermore, the printer had added an additional 4 blank pages (2 sheets) to the back of the B&W book, and 6 blank pages (3 sheets) to the back of the color book -- you don't have to pay for the blank pages, but I still dislike them. However, it's worth noting that the premium books were printed in France while the standard books were printed in the UK, so this could be down to the printer rather than the paper (meaning it might be different if you ordered in the US, for example).
That said, the printing quality for the premium color was very obviously superior to the standard color. So while I think I prefer the standard color for usability, the premium color definitely looks nicer.
The premium black and white was perhaps the most disappointing, as it appeared to be true black and white rather than grayscale, so you could see the little dots in the illustrations. It didn't look terrible, but I thought the standard black and white looked better.
I know that most publishers who offer phone PDFs are using the format as an interactive reference tool to supplement an existing product, and it would be counterproductive to offer a print-on-demand version of the phone PDF in that case (not to mention the page count would probably be huge).
But with Tricube Tales, I chose to use the phone PDF as the primary format -- it's a small game that I wanted people to be able to carry around with them at all times, and there is no "full-size" version (I do offer a tablet version as well, but it's basically the same PDF except with larger margins, higher resolution images, and layers).
For me, and other publishers who are interested in offering highly portable RPGs, I think an inexpensive print-on-demand pocketbook version is a nice option to be able to offer. Furthermore, it doesn't require too much additional effort, as you don't need to completely redo the layout.