Question

How to make entire sequence diagram messages bold at once?

Answer 1

Hello A., and all,

For that you can use style as:

@startuml
<style>
sequenceDiagram {
  FontStyle bold
}
</style>
a -> b : msg from a to b
b -> b : msg from b to b
a <- b : msg from b to a
@enduml

But that changes also the font style of all elements even: participant, group, partition, alt, note, ...

Regards,
Th.