Omni Systems, Inc. Mif2Go User's Guide, Version 55
> 31 Working with graphics > 31.5 Controlling image appearance in RTF output > 31.5.7 Specifying transparency for WinHelp 4
For WinHelp 4 only, you can choose to make bitmap graphics transparent:
; Transparent makes white bitmap pixels transparent (WinHelp 4 only)