Here's a link to Marsha's blog on texture and porosity Curl Junkie - Natural Hair Care for all types of Curly Hair!: My 2 cents on Protein/Texture/Porosity/Moisture Balance! :-) She gives some visuals--which may be helpful.
3a (Corkicelli), highlighted, fine, low porosity
SE PA

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic (now Hello Curly Curl Stimulater); Botanical Spirits Jellies, CJ Repair Me, Aloe Fix