I recently ordered in a roll of Hahnemuhle Bamboo for a new client - I hadn't used this before, my usual papers are from the Canson range.
From a batch of 15-off 10" x 10" images, 11 were subsequently rejected by the client for faint lighter bands some 3mm wide running across the full width of the print in the paper feed direction (so not head banding). Embarrassingly, I hadn't spotted the defects before the prints went out, but they are not obvious in the normal studio lighting and only in direct sunlight or very oblique lighting, and even then still very faint and hard to detect on some images. The other four prints from this batch, plus one other printed individually on a sheet offcut from the same roll, were 'perfect', according to the client.
The printer is a Canon iPF8300. As far as I can tell from test reprints on the Bamboo, the bands appear to occur at random intervals across the width of the paper roll, typically three bands on a 10" print, two somewhere around 75mm or so apart and a third some 20mm or so from the others. There may also be further bands on the same print, but they are so faint it is difficult to be certain. Neither the absolute nor the relative positions of the bands seem consistent from print to print, though I am still waiting for the reject prints back from the client to see if there is any pattern that correlates with the original print locations on the roll.
Again as far as I can tell, the bands on the test reprints do not align consistently with either the upper pressure roller locations nor the gaps between them, which was my first thought for a potential cause, nor do they resemble typical pressure marks.
I have reprinted the same test images with identical settings on a similar weight paper (Canson Velin, 315gsm), which shows no evidence of similar banding or other marks.
I have also run a further test on the Bamboo with alternative vacuum settings, and these prints show the same bands as previously.
There was also a second, unrelated defect in the margin of one of the test reprints from the centre of the roll, in the form of a jagged crease around 35mm long, which does make me wonder about Hahnemuhle's quality control.
Has anyone seen anything like this with the Bamboo paper, or has any ideas as to a potential cause? The defective samples have gone off to the paper supplier and thence to the mill for comment, but it's likely to be a little while before I have any answers. As it's the first roll of the Bamboo that I've used, I can't say whether it's a defect in this particular roll/production run - my current suspicion - or a 'feature' of the media type as a whole. In either case, the client is adamant that the prints are not acceptable in this condition, which is fair enough.
If someone would kindly tell me how I can post an image here, I'll see if I can upload a pic showing the defect when I get the reject prints back from the client. Meanwhile, any thoughts or suggestions would be very welcome.
Many thanks to all.
Malcolm