Has anyone ever seen a manufacturer who put fin marking lines on its tubes? How hard could it be to add lines for both 3 and 4 fin options at the factory? Just thinking out loud about this.
Starlight kits had pre-marked fin and launch lug lines on the tubes.
It was helpful, but ink lines and can sometimes bleed through and be seen on the finished model.
Always make your alignment lines with pencil.
Balsa Machining, Discount Rocketry/ModelRockets.us and Rocketry Works all have pre-marked and/or slotted tubes. They use laser etching so no ink bleed through problems.
Rocketship Games pre-marks and slots the tubes for their MMX kits - which makes them super easy to build, especially with eyesight well past it’s prime!