I have to admit this card was pure trial and error as I tried to make an accordian style card that ended up being an A2 size card but....still allowed me enough room on the base inside panel to use a fairly large image. I can't tell you all the videos I watched on how to make accordian style cards as there were many so I'm not sure who to give credit to as this ended up being a mish mash of different ones I liked. Here is what I ended up doing....I took a 12x12 piece of cs and cut it to 5 1/2 x 12 and a smaller piece at 3 1/2 x 5 1/2. I scored the largest piece so that I had a 4 1/4 section, two 3 inch sections and then a 1 3/4 section. This was done by just moving it around on my score pal but if you have a scoring blade on your cutter then it would be easy. I then scored my smaller piece along the 3 1/2 inch side right in 1/2 at the 1 3/4 inch mark. Once I folded my score lines then I attached the smaller piece of cs to the back of the larger piece so that the 1 3/4 section overlapped. I added my lace border so that the seam wouldn't be noticed on the front side. Here is a picture attempting to explain further:
Once you have your base put together then decorate as you like and you will end up with a 4 1/4 x 5 1/2 A2 size card. Here is a picture of the card folded and if you go here you will see my original post showing it open.
I hope this helps and next time I make one I'll try to get pictures as I go along. I like this style as you can see a peek of each layer and....wouldn't it be cute with a belly band to hold it closed?!
