Issue 3792 of Model Engineer was the first edition that used an A4 page size and so my scans have up until that point been simple A3. Prior to that then next change of size was issue 3720 when the page size switched up to 8 1/4" by 10 3/4" having been 7 1/4" by 9 5/8" for many years. I do have a box of issues from the 1960's which use the 8 1/4" by 10 3/4" format and I need to work out what other sizes have been used, but that is a later problem. The difficulty with the loss of an inch in height is that this is a size not supported by the scanner. There is an 'Auto' option, but this fails to detect the white edge reliably and gives different page heights page by page. Not at all helpful. So I need to see if there is an option to provide custom sizes to the scanner on the printer as being the best option. Failing that, I can at least scan these A3 and ignore the extra 1/2" top and bottom. Alright 12mm if we are working in metric ... For personal use then this is not really a problem, but I will hold fire running the next batch through until I get a response on the scanner options. 

Now that is interesting. Although it is not apparent from the user manual for the printer which is somewhat difficult to find anything useful in. The exercise this morning was to work out just what paper sizes the scanner on the printer can work with. A simple question one might think, but while there is a list of paper sizes in the menus, there is little in the way of actual dimensions anywhere in the manual. To try things out I ran one of the smaller format magazines through as if it was A3, and checked how much I need to trim in each direction, but I was surprised to find that the scanner had already trimmed the page length to match the area scanned so that only the top and bottom needed cropping. This prompted me to apply something I had found when looking at the page sizes, and Ledger size is an almost match for the middle size magazine, but too long. As a result, I am currently pushing these thorough the scanner and although there is a couple of millimetres extra top and bottom, it's not a problem, and in fact the magazine height varies by more than that month on month anyway, so will standardise this block of finished scans.

Only now need this for the smaller magazine unless another solution is found.
If it turns out that reducing the scan file sizes is not possible, then there is an option to crop all the pages by the same amount in PDF Arranger. This slows down the processing and in this case the niggle is that it requires a graphical input to select the size of the crop. One can't select 12mm top and bottom which would be the ideal alternative. Something else to add to the wish list on that application? Along with the option to select pairs of pages in addition to the 'old' or 'even' pages. I perhaps need to look at if I can customise any of these tools to do the job. This will be more critical when moving to the smaller page format anyway. At least the next batch of issues are still 'A3' width. The following batch is 14.5" rather than 16.5" wide so 2" extra missing on an A3 scan. Back to the pro's of being able to provide a custom setting at the scanning stage which is not difficult since there are already a dozen sizes anyway?