Over the years our floors have gained a level of crust that is very hard to clean.  We always wipe up ink when it is spilled, but alot of times a stain is left over.   Just mopping is not really enough to get the floor clean.   A month ago I decided to invest in a floor buffer.  We purchased one from Uline.  By the way, if you purchase anything from Uline, ask for a quote before you buy it.  They will almost always give a decent discount.  The floor buffer comes with a stiff red bristle brush attached to it.   We mixed some ink degradent and water 50/50, through it on the floor and cranked up the buffer.  It takes a little bit of time, but the floors we have scrubbed so far all look brand new. Maybe check this out if you like cleanliness:  https://www.uline.com/BL_8872/Floor-Cleaning-Machine?keywords=buffer