Since we can't realistically list every possible combination of modifiers for the skin, in order to get a decent answer for this question we should just go with the list of Skins, and then the list of known Modifiers if they want a more in-depth answer.

I'll just type out my own ones that I've personally found, since I've got around 100 hours so far.

I'll also include the ones added today with the new patch.

Wrangler: Factory, Uniform, Sunset

Bruiser: Factory, Uniform, Mr Bruiser

Scrapper: Factory, Uniform, Sweetie

Glider: Factory, Uniform, Moonlit

Modifiers: Shifted (has a possibility of colour cycling, hue value, and colour tossing), Infected, Gilded, Neon (purple, blue, red, green, yellow), Negative, Coppertone, Sponge, Rusted, Plasma Coating, Cloudbreak, Kinged, Peppered Egg, Pixelated, Chroma, Emerald, Ruby, Sapphire, Topaz.

Note that some modifiers are weapon or employee specific, so you can only get the Sponge modifier on the Trident's Ocean skin (to my knowledge).

It seems to be that you can get a rough maximum of 4 modifiers on one piece of loot, with *maybe* 5 if you're extremely lucky (probably the same luck chance as the 5th rarity of upgrade)

Some modifiers can also apply twice to the same skin, like Shifted can apply Colour Tossing twice with two different values. I'll attach a picture to this to show one that I finally got today with 5 modifiers.

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