The two mechanisms that do all the work, and the one rule that decides whether it still fits an envelope
9 min read
Almost every pop-up card is built from one of two mechanisms. A step fold is cut straight out of the card with two slits and reversed inward. A V-fold is a separate piece glued across the centre fold so it rises as the card opens. Everything else is decoration on top of one of those two.
Which you pick depends on one thing: whether you want the card to open flat or stand at a right angle.
The two mechanisms
Mechanism
Card opens to
Made from
Posts in a standard envelope
Step fold
90 degrees
Cut from the card
Always
Stacked steps
90 degrees
Cut from the card
Always
V-fold
180 degrees, flat
An added piece
Only if it sits inside the outline
Box or cube
90 degrees
Added pieces
Usually too thick
Layered scene
90 degrees
Added pieces
No
The first column of that table is the one people get wrong. A step fold cannot be made to work in a card that opens flat, and a V-fold is wasted in a card that only opens to a right angle. Choosing the mechanism after choosing the card is the usual reason a first attempt will not close.
The step fold
This is the one to learn first. It needs no extra paper and no glue.
Fold your cardstock in half and crease it well. Work with the card closed and the fold on your left.
Cut two parallel slits at right angles to the fold, starting at the fold and going into the card. Both slits must be exactly the same length. The gap between them becomes the width of the step.
Fold the tab between the slits back on itself, so it lies flat against the card, and crease it hard. Fold it the other way and crease again. You are training the paper, not deciding a direction yet.
Open the card. Push the tab through so it sits inside the card rather than on the outside. It should snap into a box shape as the card opens.
The slit length is the depth the step projects. Keep it under about a third of the distance from the fold to the open edge. On a standard A2 card that is roughly an inch and a half, which is plenty to hold a die-cut motif. Longer than that and the step dominates a card that still has to have something written in it.
Score the tab from the inside face. The tab folds the opposite way to the card's own fold, so it needs its crush on the opposite side. Scoring both folds from the same face is the reason a step pop-up looks torn where it bends.
Stacking two or three steps of different depths, each with its own pair of slits, gives a staircase. The rule is the same for each one, and the deepest step goes nearest the fold.
The V-fold
Use this when the card has to open flat, which includes most cards you intend to post.
Cut a separate piece of cardstock and fold it in half.
Open your card flat. Put the folded piece against it so that the fold of the piece meets the fold of the card, and the piece sits at an angle across it, like a V lying on its side.
Glue one wing of the piece to the left half of the card and the other wing to the right half. Glue one wing at a time and let it set before doing the second.
Close the card slowly. The piece folds itself.
The angle is the whole adjustment. The shallower the V sits relative to the card's fold, the further forward it throws the motif when the card opens. A steeper angle makes it rise higher but travel less. Cut a test piece from scrap and try two angles before committing the good paper, because it is much easier to see than to describe.
The one rule that decides whether you can post it
A step fold is cut from the card, so the paper was already inside the card's outline and always will be. It cannot protrude.
Anything glued on can.
When the card is closed, every added piece must sit inside the card's outline. Not level with the edges, inside them. A V-fold whose wings reach past the open edge will stick out of the envelope, catch, and tear the first time it is handled.
The test takes two seconds and almost nobody does it: close the card before you glue the final edge. If anything pokes out, trim it then, while the piece is still moveable.
Thickness matters as much as outline. A card with several layered mechanisms can pass the outline test and still be too thick to post at the letter rate. If a closed card does not sit flat under a light book, it is going to attract a surcharge.
Cardstock weight
Pop-ups want lighter paper than a flat card, which surprises people.
Card base: 80 lb cover, around 216 gsm. Same as any card.
Mechanisms: 65 lb cover or lighter. A mechanism cut from heavy stock fights its own folds, springs back instead of snapping into position, and cracks at the crease.
Decoration glued to a mechanism: as light as you can get away with. Weight on the end of a V-fold makes it sag open.
If a step will not hold its shape, the paper is almost always too heavy rather than too light. More on choosing weights in how to cut cardstock with a Cricut.
Other fancy folds worth knowing
Easel cards are not pop-ups but solve a related problem: displaying a card upright. The card front is hinged partway up so it folds forward into an easel, and a small piece glued to the base acts as a stop to catch it. The stop is the part beginners leave out, and without it the front simply slides flat.
Waterfall cards use a pull tab. A strip of panels is attached so that pulling the tab releases them one at a time and they cascade down the front. The mechanism is a series of hinges rather than folds, and it needs a card base that opens flat to hide the tab travel.
Both fold flat and both post normally, which is why they are worth having alongside the two pop-up mechanisms.
Sizing and envelopes
A pop-up card is sized exactly like a flat one. The mechanism lives inside the closed footprint, so an A2 pop-up takes an A2 envelope. Full card and envelope dimensions are in A2 card size and every standard card dimension, and if you would rather make the envelope than buy it, how to make an envelope from paper has the blank sizes.
For the mechanism itself, a cut file saves the fiddly part, which is getting two slits exactly the same length and exactly parallel. A millimetre of difference there is visible in the finished step. Browse the free SVG collection or the free cut files for Cricut page. Every download includes SVG, PNG, DXF and JPG, so a mechanism can be scaled to a card size that is not standard without losing edge quality.
Frequently asked questions
How do you make a pop up card? Fold cardstock in half, cut two parallel slits of equal length at right angles to the fold, crease the tab between them in both directions, then open the card and push the tab inward so it forms a step. That is the step fold. For a card that opens flat instead, glue a separately folded piece across the centre fold at an angle, which is a V-fold.
What is the difference between a V-fold and a step pop-up? A step is cut out of the card itself and works in a card that opens to a right angle. A V-fold is a separate piece glued across the centre fold and works in a card that opens flat. They are not interchangeable, and picking the wrong one for how your card opens is the usual reason a first attempt will not close properly.
Will a pop-up card fit in a normal envelope? Yes, if every added piece sits inside the card's outline when it is closed, and the closed card is under a quarter inch thick. A step fold always fits because the paper came out of the card. A glued-on V-fold only fits if you sized it to.
What weight cardstock is best for a pop-up card? 80 lb cover for the card base and 65 lb or lighter for the mechanism. Heavy stock in a mechanism springs back instead of holding its position and cracks along the creases. If a step will not stay up, the paper is too heavy rather than too light.
Why does my pop-up card not lie flat when closed? Almost always because a glued-on piece extends past the card's outline, or because the mechanism was creased in only one direction. Close the card before gluing the final edge so you can still trim, and crease every mechanism fold both ways before assembling.
Why does my step pop-up crack where it bends? The tab folds the opposite way to the card's own fold, so it has to be scored from the inside face. Scoring both folds from the same side crushes the fibres on the wrong face for one of them, and that fold tears rather than bends.
What is an easel card? A card whose front panel is hinged partway up so it folds forward and props itself upright, with a small stopper glued to the base to catch it. It is a display fold rather than a pop-up, and it folds flat to post.
How does a waterfall card work? A strip of overlapping panels is anchored at one end and connected to a pull tab. Pulling the tab releases the panels one at a time so they cascade down the card front. It needs a base that opens flat so the tab has room to travel.
