Moving SuperStamps into Snagit Mac 2018 is easy, simply follow these steps:

1) Download the file 

2) Unzip the file

3) Make sure to Completely exit Snagit  

4) Right click on the Snagit app in Applications  

5) Select 'Show Package Contents’  

6) Go to Resources/Stamps and copy the contents to there.  

7) Re-open Snagit

Alternatively, you can also try the following:

1) Download the Superstamp package for Mac.  

2) Once downloaded, double click the the file to install them.  

3) The file should be named something similar to "SnagitStampsv4.snagitstamps."  

4) Once installed the stamps will be available under the Stamps tool in Snagit, under the Custom category.

You may access the information here: