I made this card at a Make & Take at the show I went to recently. I've made different varieties of this step card a few times over the last year. Recently, a friend and I came up with the same thought. What if we made this a landscape card instead of portrait? That was all the challenge I needed to figure it out. Easy enough. The additional challenge was to make it fit in a regular 1/4 sheet envelope. Got it, did it, done! I've included a pattern for you to print out (you will need to enlarge) as well as my sample. I did use one of the ATC's I had left over from the show so putting this together was quick and easy. The best part is that you make it from a piece of card stock that's 5-1/2" X 8-1/2" just like a regular 1/4 sheet landscape card.
On the pattern below you will cut on the solid lines and score on the dashed lines. You can do this on your trimmer. The side panels are each 1" wide but you can change that, just don't change the score lines or the length of the cut lines. The score lines on the side panels from the bottom of the front of the card are at 1", 2", and 5-1/4". The score line at the top of the middle panel is at 4-1/4". The cut line is from the 1" mark to the 5-1/4" mark. I did this all on my Scor-Pal and trimmer. If you would be interested in seeing a video on how to make this card, leave a comment and if there's enough interest I'll work on one for you.
I found it easier to score all my lines (including the ones I planned to cut), then cut the ones that needed to be cut. Embellish however you like. Again, I have used simple lines on mine. Give it a try, I know you'll love it.