The vast majority of engine long blocks are now made of aluminum. Aluminum of course is much softer than steel and therefore can more easily be gouged or damaged.
No where is it more critical to be careful not to damage the aluminum than the mating surfaces between engine sub assemblies; essentially anywhere a gasket is used.
The key when removing old gaskets is to use a material softer than the base material you are working with. Most people will tell you to get a razor blade, or a metal tipped scrapping tool and to be “careful”. I am all for being careful, but using a material (steel) that is much harder than the base material isn’t something I recommend.
Automotive alloyed aluminium may be soft, but its not nearly as soft as normal brass; yet brass is much stronger than a paper, cork or rubber gasket.
Motion Pro makes a brass tipped scrapper Part No. 08-0601 for just the task:
This is tremendous. I wish I had known about this years ago! Scraping gaskets from aluminum is always so tedious and nerve-wracking, especially when dealing with something like an expensive classic cylinder head.