Thanks to the fine folks here at the GIS SE, I have managed to batch process a load of ASC files into raster hillshade TIFs. However, while they look fine on screen, when printed they are very pixellated - they are too low a resolution in the printing sense. Is there anyway I can increase the resolution so they print well?
Raster -> Projections -> Warp; set the output file type to TIFF and set the source SRS and target SRS to the CRS of the input layer. Tick the "Resize" box and set "Width" to the required width, you can set "Height" to zero if you like, which will maintain the original aspect ratio in the output file. As a resampling method I normally use "Near".
Added later: but try other resampling methods too. Bilinear, perhaps. N.