What foam is best for helmet padding?

I have a pair of ODST helmets, but they are not wearable because they have no padding. I tried using very thick and coarse packaging foam (The kind that holds computer parts in place while in the box). That was a failure because they were too stiff, difficult to cut cleanly, and uncomfortable

FanFlex: Lightweight flexible crests and patches that fold easy. - FanTex: An all-new super comfortable soft fabric. - FanFit: The authentic on-ice

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FanFlex: Lightweight flexible crests and patches that fold easy. - FanTex: An all-new super comfortable soft fabric. - FanFit: The authentic on-ice

Helmet Padding Memory Foam Pad Protective Mat Helmet Padding Kit for ACH MICH Team Wendy FMA EXF Helmet

FanFlex: Lightweight flexible crests and patches that fold easy. - FanTex: An all-new super comfortable soft fabric. - FanFit: The authentic on-ice

Shrey Match 2.0 Cricket Helmet Navy EVA Foam Padding

FanFlex: Lightweight flexible crests and patches that fold easy. - FanTex: An all-new super comfortable soft fabric. - FanFit: The authentic on-ice

Hard Head Veterans Comfort Plus Helmet Pads (Ballistic Liner Upgrade) Fits mich, Ach, Fast, ate and Other Helmets

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Hard Head Veterans Microlattice Tactical Helmet Pads | Fits mich, Ach, Fast, ate & Other Kevlar Helmets | Military Helmet Ballistic Liner Upgrade

FanFlex: Lightweight flexible crests and patches that fold easy. - FanTex: An all-new super comfortable soft fabric. - FanFit: The authentic on-ice

ImpaX Extreme Pad Set For MICH / OPS-Core / ACH / M-Tek Helmet