And the output of cups is below. I have yet to really figure out what it means except I suspect this section is somehow relevant to my woes.
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: opened PPD file "/private/etc/cups/ppd/EPSON_SC_P800_Series.ppd"...
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: PreferredRotation = -90
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsPageSize=[595.2 841.8], cupsImagingBBox=[8.4 8.4 586.8 833.4]
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: width=595.2, length=841.8, top=8.39996, bottom=8.4, left=8.4, right=8.40002
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsWidth=5784, cupsHeight=8250
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: languageLevel = 3, mediaBox.size.width = 595.2, mediaBox.size.height = 841.8
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: colorspace = 1, bitsPerColor = 16
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: Vendor matching mode is ON and the handoff color space requested is sRGB.
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: band width = 5784, bytesPerRow = 46272, band height = 226, height = 8250
D [15/Jan/2016:16:39:19 +0100] [Job 11] cgpdftoraster: context width = 5784, height = 226, bitsPerComponent = 16, bitsPerPixel = 64, bytesPerRow = 46272, bitmapInfo = 4101, resolution = (720.000000, 720.000000)
D [15/Jan/2016:16:39:19 +0100] [Job 11] HWResolution = [ 720 720 ]
D [15/Jan/2016:16:39:19 +0100] [Job 11] ImagingBoundingBox = [ 8 8 586 833 ]
D [15/Jan/2016:16:39:19 +0100] [Job 11] Margins = [ 8 8 ]
D [15/Jan/2016:16:39:19 +0100] [Job 11] PageSize = [ 595 841 ]
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsWidth = 5784
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsHeight = 8250
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsBitsPerColor = 16
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsBitsPerPixel = 48
D [15/Jan/2016:16:39:19 +0100] [Job 11] cupsBytesPerLine = 34704
D [15/Jan/2016:16:39:19 +0100] [Job 11] band = {0, 802.4; 595.2, 22.6}
D [15/Jan/2016:16:39:19 +0100] [Job 11] Erasing band to white...
D [15/Jan/2016:16:39:19 +0100] [Job 11] EraseContext [0 0 5784 16500]
D [15/Jan/2016:16:39:19 +0100] [Job 11] displayList=0x0
D [15/Jan/2016:16:39:19 +0100] [Job 11] drawSheet(c=0x7fed33211370, document=0x7fed33000be0, pageNum=1, mediaBox=[0 0 595.2 841.8], band=[0 802.4 595.2 22.6], nup=0x0, pageMap=0x0, fitToPage=0, preTransformP=0x0, rotation=0)
D [15/Jan/2016:16:39:19 +0100] [Job 11] Drawing unscaled page.
D [15/Jan/2016:16:39:19 +0100] [Job 11] docMediaBox=[0 0 1369.13 935.433]
D [15/Jan/2016:16:39:19 +0100] [Job 11] scaled rect=[0 0 1369.13 935.433]