I don't know... what do you expect that would do? Remove the borders? No tick labels?
I mean "no axis", just lines and points.
I'm planning on adding some logic so that plot(..., axis = nothing) will be the same as plot(..., ticks=nothing, border=nothing)
using Plots; plot(rand(10), axis=nothing)

Just a note for others reading this, axis=nothing was not enough to remove guide lines when plotting an image. I worked around it by also setting foreground_color_subplot to white like this:
plot(colorview(RGB, rand(3, 300,900).*10.0), legend=false, axis=nothing, foreground_color_subplot=colorant"white")
Actually it turns out setting border=:none does what I needed. Note that border=nothing does not work.
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I'm planning on adding some logic so that
plot(..., axis = nothing)will be the same asplot(..., ticks=nothing, border=nothing)