How well can triglycerides be resolved using TLC?
If you work with normal phase TLC, you may lower the polarity of your mobile phase, and instead of mixing ethyl acetate with petrol ether, you may give diethyl ether / petrol ether (like 5:95, v/v) a try.

Some of the TLC manufactures even provide databases, pointing towards publications were compounds of interest were successfully separated.  Often, these references refer to a separation on TLC-scale.  CAMAG's CCBS Database is one noteworthy example.