As helpful as a bigprintbutton in the Messages app would be, that’s not how this works.
Make Screenshots From Your Phone
Good for capturing context.
you might mark up the screenshot.

Doesn’t require a computer or special app.
Might require more ink than you want to use.
A bit much if you just need to print one message.

If you’re unable to print from your phone, it might be because your printer isn’t wireless.
In that case, email it to yourself and print it from a desktop computer.
See ourHow to Send a Picture in Gmailguide if you need help attaching the screenshot to an email.
OurEasy Way to Print a Single Gmail Messageguide explains how to print the screenshot from your system.
Other email accounts work similarly, even if you don’t use Gmail.
Copy Texts to a Computer
Good for collating messages from different conversations.
you could edit the message before you print.
Ideal for wired printers.
Requires you to complete several steps.
Might not hold up in court if this is where the messages will end up.
Press and hold any text to see a menu with options.
With the text copied, you now have several options for getting it onto your gear.
The idea is to put the text anywhere that you’re free to also access from a computer.
after you snag the document open, go toFile>Print.
This is really easy to do withMessages for Web.
Similar to the other methods above, you’re able to use this technique to print highlighted texts.
An alternative method, if you don’t want to use Messages for Web, isMicrosoft Phone Link.
Lets you pick certain conversations to export.
Printing is supported from your phone or a computer.
Overkill if you just want to print a few messages.
Most trustworthy method of proving conversation history.
Use theSMS Backup & Restore appto export all your texts, or messages from just specific people.
Our articleHow to Save Text Messagesshows how to use this app if you want a walkthrough.
Tap and hold on the image.
Tap the three dot button in the top right.