Hey ! i never had problems with sticking the print to the platform eventough i switch a lot of resins.
Ive been printing in grey resin V4 for a month, more than one liter and when i wanted to use tough resin, i have attemped to print the same model 3 times and it stays sticked to the tank.
Thins i’ve done after this to check if the problem was solved:
1-Updated preform and firmware to latest version
2-clean build platform with ipa and removed rests of grey resin.
3- used the scraper in a 45 degree angle to cleam the bottom of the resin tank
The think is that i use a LOT my form 2 to work and i dont want to touch the fine tunning tool because im afraid i will have problems with grey resin
Tough is definitely a bit more challenging to print than the standard resins, and adhesion to the BP is one of the difficulties although it is easy to deal with.
Your 2nd point make it seems like you had leftover grey resin on the BP before using tough, this can definitely cause issues. I clean my BPs thoroughly with fresh IPA and a clean paper towel after each print and make sure the platform isn’t sticky before putting it back in the printer.
You should not be afraid of using the Z-offset tuning parameter on the printer, especially since you’ll be using a negative offset bringing the BP closer to the tank) which will at worse increase the adhesion of Grey parts to the BP, which shouldn’t be too much of a concern.
It is also possible that your BP is slightly concave or convex, and so printing a very small part (small surface area in contact with the BP dead center or in one of the 4 corners may lead to issues not present elsewhere on the BP. Try printing near the middle of the sides of the build area to see if it prints correctly, in which case you should tune the Z-offset value to get the parts to print everywhere.