Help with object sticking to bed

[Sue h]

Hi,
my son is only 12 and recently got a 3D printer. He’s achieved several objects so far but occasionally and seemingly for no reason (as he hasn’t changed anything) the object seems to start to stick to the printer bed and messes up. I see that some people use some sort of oil on the bed? When I google I can only find info on lubricants for the mechanics and not the bed itself. Could somebody help us?
Thanks

[sreeves]

It sounds like it's not sticking well enough. More details would be helpful. Is he using blue painters tape? Does it have a heated bed? What is the bed surface?

[Johann]

I think it would typically be a type of glue, I've used a regular glue stick in the paste and has worked fine. I'm not 100% sure on your issue tho because you said that it started to stick to the bed, and thats what you want your print to do. Could you clarify? Thanks!