Hi!
As we well know, each printing company has it's own way of presenting their ships and the instructions to build them. For instance, Wilhemshaven has baseplates shaped for the hull at the waterline and after installing the Keel piece which profiles much of the ship, build upwards from there. Now, Modelarz and some other Polish kits have you build a strongback that is triangular in cross-section and may be three or more elements long.
One of the things I must bring to your attention here. When Doing this strongback, be careful. They do not tell you for instance, that the piece that closes up the construct MUST go on the inside of the part! This piece is a strip which you crease and ,Yes, Make sure it is dead on straight.! Put Aleens (my glue of choice) on it sparingly , but completely, then take a Long Skewer or straight piece of thin wood and rub it into place making sure not to split the joint. Do Not touch, for twenty four hours.
When cutting out the frames they mark an area for you to cut out and fold to create an opening to slide the frames on. Follow the instructions exactly as to the direction of the glue leaves on the center opening and Yes, If you can, gently place something on top to hold those frames till dry. Be careful here! If the item or items are too heavy, the top of the frames WILL collapse. Make sure also that those openings are cut enough that they slide on gently but not sloppily!
Then add the Bottom Frame ship waterline edge. Do not use a great deal of glue and only do two or three frames at a time making sure they remain square. Also, and I cannot remind you paper modelers out there ,enough. Whatever you build, Make sure that when you bend tabs, Do so On The LINE and that they are square! And in the direction they indicate!
Good Building!