Setting the max size

In settings (I am using DropDMG v.3.1.4), how do I specify for a standard .sparcebundle a max size? So, when I right-click a folder and want it to be converted to .sparsebundle automatically? As it is by default, DropDMG takes the files and processes them, then adds a minor “buffer” to the max size. I want to specify a default - say 1GB for each .sparsebundle, so that I can add files to that .sparsebundle over time (the entire purpose of read-write formats is to be able to write, and I need more writable space). If I create a .sparsebundle from an empty folder, the max size is just under 6MB, which is useless.

How can I do this? I’m puzzled…

When you create a disk image from an existing folder, DropDMG automatically sets the size (with a little extra). To choose the size yourself, you would need to use the New Blank Disk Image… command.