Wood picture frames don't typically come with the means to hold the contents in the frame. You must provide it yourself with one of these devices.
Tools for Securing the Contents of Picture Frames
Picture Framing Do's and Don'ts - Essential Tips and Mistakes to Avoid
Fletcher PushMate Point Inserting Tool
Fletcher Glazier Points
What Tools do I Need to Assemble a Picture Frame?
How to Hang a Picture: 5 Tips for Hanging Photos on the Wall
Tools for Securing the Contents of Picture Frames
How to Picture Frame a Deck: Proper Techniques
Picture Framing Equipment and Supplies, Page 7 of 10
Artist's Tools Bag, Xiem Art Bag, Art Supplies Carrier, Ceramic
FRAME FITTING, SECURING THE CONTENTS OF A FRAME
How to Hang a Picture
Loops & Threads Scroll Frame Cross Stitch Embroidery 9 x 18