Even if you feel like you're doing everything 'right' with printmaking, sometimes little things pop-up here and there that are incredibly frustrating and can knock your print confidence.
Something that popped up again for me recently is what I call the ink 'halo'. I used to only think this happened when you used a printing press but today it started happening when I was rubbing a wooden spoon.
You can see an example of the ink 'halo' below.
You can see it running the whole length of the top of the blackbird, from his head down to his tailfeathers - it looks like a white line on your paper. After much trial and error, I've discovered that this seems to appear when I've been pressing too hard (either when printing y hand or with a press) and I've forced the ink over the edge of the carved area. This has caused the ink to bleed, causing what appears to be a white line.
When I first inked up this blackbird block, there appeared to be nothing wrong - I checked the ink in the light and couldn't see anything amiss. When I began rubbing the back of the paper though, it was bleeding through the paper more than I'd like- a sign that I was burnishing too hard.
It's a thin Japanese paper so some bleeding will occur naturally- but I had been rubbing far too hard.
The printing part of linocut is quite Goldilocks in that you need enough pressure and enough ink to produce a good print. It can take a while to find that balance and still sometimes after years of printing, I get it wrong- as happened here.
Going forward, how I fixed this trouble spot was to add a thin layer of black ink- burnish gently (rub the back of the paper)- lift the paper and add another thin layer of ink and burnish again. This way I'm keeping the ink nice and thin and not having to tub too hard.
If you have already printed the design and found the white line- what you can do is to lift the paper partly off (still keeping it still- this is where a registration board comes in handy) and tilt your roller when you ink up so that you are only inking this trouble spot.
This is shown below. Doing this will allow you to fill the white space on your paper created by the ink 'halo' to allow you to salvage that particular print.