Msi two times larger than msm

Question

I have a .msm of 100MB and when I build my WiX project I get a .msi of 200MB Here some code:

Answer 1

So when you set compression to high the MSI is 100MB or about the same size as the .MSM? So what's the problem here?

The merge process extracts the files from the MSI and places them into the MSI. If the MSM had a higher compression setting then the MSI you could expect the package to expand in size.