Hi all, hoping you might be able to help me. This seemed like the closest Tildes category to post in. Maybe a year ago, I noticed I had tracked something into my apartment on my shoes and it left gunk on the floor. I cleaned as best I could and most of it came off but one major spot stained. Everything I tried wouldn't take it off. Over the last year it darkened and is the darkest spot in the photo.

I was never able to clean it off or figure out exactly what I got stuck on my shoe to cause it. Until a couple days ago when it happened again. And eventually I put two and two together. There's some type of tree that drops some kind of nut or seed near the parking area and when I walk to my trunk after parking I accidentally stepped in one which smushed into my shoe and tracked into the apartment. I don't know what kind of tree or seed it is, but that's what stained it.

Now that it's happened again it's even worse and I cannot for the life of me clean this off. I have tried 409, rubbing alcohol, Goo Gone, bleach, hydrogen peroxide and nothing cleans this crap off more than it is in the photo. Even scrubbed it with a sponge scrub pad and nothing. It's a smooth surface so it's not like a chunk I can scrape off, it's just like stained the laminate floor.

Any suggestions on what else I can use to clean this gunk once and for all without damaging my apartments floor?

Thanks! Here's the photo: https://imgur.com/a/pQ5hw36

I like a bit of M.C. Escher art, and I was looking for some Escher images when I stumbled across this old blog post by someone who designed and made his own Escher-inspired floor tiles. Fascinating stuff!

Here's the main page, showing a photo of the finished floor: https://danceswithferrets.org/geekblog/?page_id=911

Then there's 8 blog entries, showing the steps he went through from initial idea to finished product.

As a bonus, here's a simple guide I found, which explains how Escher designed & made his tiles: http://static1.squarespace.com/static/5754f47fcf80a16bffa02c45/t/57c6b680f7e0abc8f6ac6993/1472640669212/Escher-tiling-instructions.pdf

It's so simple when you know how! But there's obviously still some artistry involved in deciding what shapes to cut & paste.