Maramarama te tautuhi i nga tawhā whakahaere o to punaha waipēhi: te pehanga teitei, te auau o te pupuhi, te pāmahana, te papapāho, te waahi ararere.
I runga i aua tawhā tohua te momo ngongo ngongo (hei tauira, ko te ara iahiko mahi matua e whakamahi ana i te momo torino, te peka-waenganui e whakamahi ana i te momo whiri, te raina whakahoki mai i te ngongo whakahoki, te raina horoi matū e whakamahi ana i te werawera, i te ngongo motuhake ranei).
Whakaarohia te motuhake o te taiao (matū, abrasion, UV, anti-static etc) ka kowhiri i te rawa uhi tika, ngongo ngongo motuhake ranei.
Manatokohia nga whakaurunga mutunga, te waahi whakaurunga, te radius piko iti, me te tuku mo te waahi whakakapinga tiaki.
Whakaritehia nga waitohu whai tohu pono, tautoko raraunga me nga whatunga ratonga ao ki te whakaiti i te tupono.