Hi
I have a garden shed recently purchased. Standard shiplap diptreated. I have already painted the exterior after it was assembled last early autumn with creosote.
As the weather now improves, I'm looking to paint the interior with cupranol in a nice bright shade.
My question is how do I prevent this very light colour seeping through the joining etc to the exterior very dark colour... Aside from 'being careful and not loading my brush, is there any tips you may have that I'm overlooking?

Thanks 😊

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