i copied and pasted this from the actual tfcon toronto site,under the "art.custom and costume contests".
please note,this set of rules is from a few years ago but generally don't change.
there's also a bit more that gets judged like actual time spent,if it shows,finish,execution,etc.
in other words,every piece is looked over like a fine jeweller in almost every aspect
Art, Custom and Costume Contest Info
TFcon Art and Customs Contest
This year sees the return of the TFcon art and customs contest. Entries may be submitted from 9 am until 12 pm the Saturday of the convention. After 12 pm all art pieces will be judged by the TFcon Art Judges. The winner will be announced at a time on the event schedule. This year there will be 3 categories for the art contest attendees are welcome to enter, 2D, 3D, and costume. All entries are to be PG-13. Pieces previously entered cannot be entered again. No collaborative entries, the piece has to be 100% your own creation. Limit of two entries per person.
2D entries can be anything from a painting, black and white drawing, color drawing, computer render print out, basically anything that’s on a flat piece of paper qualifies for this category. It is preferred that any 2D entry be mounted, framed or in a protective covering. 3D entries can be anything from a diorama, kitbash/custom, toy repaint or statue.
2D entries will be judged on originality, perspective, creativity, lighting/shadows, application of color/tones, detail, realism/suspension of disbelief and the judges overall impression. 3D entries will be judged on detail, originality, use of color, proportions, realism, use of materials, innovativeness, neatness and the judges overall impression.
The 3D art contest prizes will be custom made trophies from TFcon. These prizes will only be offered to 1st, 2nd, and 3rd place entries so be prepared to come ready to compete!