The collar body is polypropylene sheet. The material choice changes the surface: how clear it is, how it handles glare, and whether the color is part of the sheet.
Pick the sheet before you lock artwork. A logo that reads on clear PP can disappear on a dark opaque color.
Clear PP
Clear PP is the standard transparent sheet: 100% transparent PP, flexible, and easy to fit on the patient. It is the usual base for clinic and private-label programs that need the collar to stay see-through.
Clear does not mean a tested light percentage, a resin grade, or a medical-device claim. If a buyer needs a certificate, confirm it for that destination before it is written into the order.
Diagonal PP
Diagonal PP is the textured transparent sheet. The diagonal surface adds grip and cuts glare on the collar. It is the pair to smooth clear PP, not a different closure or a different size run.
Use diagonal when the buyer wants less shine on the cone. Confirm the texture on a sample if the artwork has fine lines.
Frosted PP
Frosted PP softens the look and reduces shine while staying translucent. It is not an opaque sheet. Wound area and print will read differently than they do on clear PP.
Ask for a frosted sample next to the clear sample if the brand color depends on how much of the sheet shows through.
Colored PP
Colored PP can be translucent or opaque, matched to a reference you send. It is a sheet color, not a printed ink layer. Printing can still be added on top.
Send a physical color reference or a Pantone target, and state whether the sheet should stay translucent or go opaque. Color approval happens on the sample.