Hi there thanks for posting in the Lucid community! To clarify are you referring to sticky note shapes on your board that you'd like to make invisible during your retrospective session? If so I recommend utilizing a Frame to contain these sticky notes (and other objects if needed) then using the Hide function to cover the contents. Simply add your objects to the frame then click Hide. 

After doing so the contents of the frame will be hidden.

When you're ready simply click the same button to un-hide the contents and make them visible. I hope this helps! Please let me know if you have any additional questions. 

Hi @furbacherova! Abby here from Lucid. I thought you, and others who might come across this topic in the future, might be interested in Lucid’s Agile Trusted User Group. This group is made up of passionate, experienced users who regularly use agile methodologies in their work. As part of this group, you’ll have the opportunity to connect directly with Lucid’s product team and share insights about your workflows, pain points, and needs, shaping the future of Lucid’s agile tools. 🎉 You can learn more and apply here. Thanks!