Earlier quoted context omitted.
I think you have it backwards, if I am interpreting your very brief statement fully correctly... If you are building a library and you want it to be open source but also usable by products that are not open source, you can use LGPL. If you are building a proprietary library and you want to keep it proprietary, but link it into a GPL application, I think there is nothing is stopping you from doing that. You still have…
You read the previous statement backwards. OP meant: dynamic linking allows you to use LGPL libraries with proprietary applications; to use GPL libraries in your application you have to make your application free even if you are linking dynamically.
> .dll won't help with GPL, only with LGPL (IANAL)
Was pretty much totally ambiguous about what exactly was meant.