I found this tutorial for Side Spring Card on Splitcoast Stampers, so thought I would share with you.

Side Spring Card

by Beate Johns

Create a unique card fold with a few score lines.

Supplies

• One 5 1/2" x 8 1/2" piece of cardstock
• Scor-Pal™ or other scoring tool
• Additional cardstock and/or patterned paper to decorate the card
• Stamps The Greeting Farm Build-a-Onesie Boy used here)
• Adhesive
• Embellishments

Step-by-Step

1. Step 1

   Score cardstock at 2 3/4" on the short side.

   

2. Step 2

   Turn cardstock 90 degrees and score at 2 3/4"

   

3. and 4" on the long side.

   

4. Step 3

   Fold cardstock in half on the long score line.

   

5. Step 4

   With the shorter panel to your left, line up the top of the second vertical score line with a Scor-Pal™ groove. Line up the bottom of the first (left) score line with the same groove and score a diagonal score.

   

6. Unfolded your cardstock should look like this.

   

7. Step 5

   Pre-score both diagonal score lines mountain style.

   
8. 

9. Step 6

   Pre-fold both vertical score lines valley style. Your cardstock should look like this.

   

10. Step 7

    Fold the left panels up.

    

11. Now fold the left panel over the right side of your card base.

    

12. Step 8

    Decorate the front of you card.

    

13. Step 9 (Optional)

    Decorate the inside of the card.

    

14. Step 10 (Optional)

    Unfold card and add adhesive to the lower right scored triangle. This will help to keep your image square right next to the card base.

    

15. Hint:
    If you adhere the square to your card base, the card can only be opened partly. Try using re-positionable adhesive so this won't happen.
    
    Or if using regular adhesive, make sure you write your message in card before adhering the square to the base.

    

16. Step 11

    Your card is finished.