a quality printer is def a must - attached below is a pk done with my laser printer using 2.5 pt font - now I would argue any blurriness is due to my camera but I believe that even on 10x zoom it is readable. This was printed several years ago and has been sitting in water (except for when I take a photo). It is quite legible under a magnifying glass or if you have a decent phone camera. My point is, I dont use 2.5 pt font when doing keys - it is usually 6 pt font this was done to see how small I could go while keeping it readable. I have seen PK's done in like 10 pt font that when peeled are completely unreadable