Here is all the measurements you need to make your Pink Frog 15cm x 42cm Unscored Card Blanks into C6 Card Blanks. This means you get even more versatility for your card blanks.
Card Fold Instructions to turn 15cm x 42cm to C6 Cards
Firstly cut your 15cm x 42cm Card Blanks to 15cm x 21cm

C6 Half Fold Score on long side at 10.5cm

C6 Tri-Fold Score on Long side at 7cm and 14cm.

C6 Z Fold Score on long side at 5 cm and 10cm

C6 Double Z Fold Card 1—score on long side at 5.5cm and 10.5cm
Card 2—Cut to 10cm x 21cm and score on long side at 10.5cm and 15.5cm
and off set join both pieces together.

C6 Bar Double Z Fold Score on long side at 5.5cm and 10.5cm
and then cut to measure 13cm x 21cm
and off set join both pieces together.

C6 Gate Fold Cut card to 15cm x 20cm and score on the long side
at 5cm from each end.

C6 Side Gate Fold Score on long side at 7.5cm and 18cm

C6 Easel Card with Mat Score on long side at 5.5cm, then at 10.5cm
Cut an extra mat at 15cm x 10.5cm and a stopper of your choice.

C6 Pop Out Card – Card 1 – Score on long side at 10.5cm.
Card 2- Score on long side at 10.5cm and then in at 5.5cm at each end.
Then attach card 2 to card 1

Easy & fast Instruction sheet