How to use PEKOKO print primer to make the mini handheld color printer print on metal,glass,plastics

Hello!Pekoko Family!
Today are going to teach you how to use print primer to make the mini handheld color printer print on metal,glass,plastics.
1.spray the print primer on the surface you would like to print，spray as thick as possible
2.wait it to dry,as usual,it will take 5-15 minutes.It depends on the Temperature, ventilation, density of printing material。
As we tested as follows:
Temperature：16°C，
metal:10minutes
plastic:5minutes
Glass:15minutes
3.After it dried:use pekoko k1 mobile color printer print whatever you want to print on it,
we have printed a small picture on it
4.wait it to dry;
Temperature：16°C，
metal:20minutes
plastic:10minutes
Glass:30minutes
5.I tried to erase these pictures with my fingers，But I failed
6.Then I put all them in water,They also can't be easy to be erased
You can have a try at home,and tell me your Temperature and minutes,Thank you very much!!1