C-Command Software Forum


I installed DropDMG just before Christmas and I have to admit I didn’t give it much time. I’m back to looking at it but my trial has expired. My fault but it’s going to mean that I have to ask if things can be done.

I develop Java apps and use an application called install4j to create native installers for macOS.

I have a .dmg file that contains a single installer .app file.

I would like to add to my command line build script the ability to give the .dmg a custom disk icon and also set a background image when it’s opened.

I have to admit I failed to understand how to do this when I had a short period of experimentation.

It is possible to extend my trial so I can try this out for myself or can someone assure me that it’s possible and not tooooooo difficult. I got rather overwhelmed with the number of buttons and options in the GUI - perhaps missing a “wizard” to do what I need.

Many thanks


To add a custom background picture, you would go to the Layouts preferences, click + to make a new layout, and click Choose… to select your image file. Then select the new layout in your configuration.

To add a custom icon, you would go to your configuration and check the Custom volume icon box. Then click the Set Icon… button, select the custom icon that you want to use, and the select the folder where you want the icon file saved (i.e. the folder containing your installer that you would pass to your build script).

I’ll message you a temporary serial number to extend your trial.

Thanks for that it will be most helpful.

Sorry - where do I look for the message ?

The forum should notify you, or you can click on Messages from your profile page.

I have the trial working again - many thanks. Although I would like to think of myself as an experienced mac user and developer I have to admit to being rather lost when it comes to using DropDMG to do what I want.

As I mentioned in my first post I develop in Java and create a native Mac installer .DMG package using a tool called Install4j.

The actual name of the .dmg I create will change over time as it includes the version number of the application in the filename - however if that complicates things I can use a fixed name.

I would like to automate a process with takes this plain dmg file, changes the disk image icon and sets a background wallpaper. The dmg will have an .app installer within it at the start of the process.

I am guessing that if I can create a config which defines these changes to the dmg I would be able to call it from the command line ?

Is there a step by step (click by click) guide as to how I would make these changes. I have so far dragged my dmg and png images onto the DropDMG gui and experimented with layout but without success.


This may be part of the confusion. DropDMG is not designed to change the content of an existing .dmg file. It’s meant to—and this produces a more compact file—create a fresh disk image each time. The general workflow is to put your installer package in a folder (and into the layout) and drop the folder onto DropDMG. The process is outlined here, although some of the steps/options may not apply to your situation.

Or, from the command line, you would use something like:

dropdmg --config-name <your config name> <path to folder with installer>