With the 1960 base, trailer numbering started in the TU- series, possibly at TUA-100.
After TZZ-999 was reached, the series continued from TAA-100.

All of the plates up to TZZ and then from TAA as high as the TKD series used experimental reflective sheeting with small beading which was "rough" to the touch.
To validate these plates, blank metal tabs with year stickers were used, because the stickers themselves had trouble adhering to the beaded/rough surface of the plates.
There are listed in alpha order on this page.

There was a series of plates that was made by putting the reflective sheeting on a black painted aluminum base plates.
These are extra black blanks from the late issue 1957 base.

The black-backed trailers seem to be in a contiguous group - starting somewhere after TBH and going to at least TCA.

Dave Zullo

Dave Zullo

Dave Zullo

Dave Zullo

Colin Schaefer

Colin Schaefer

Dave Zullo

Dave Zullo

Between TCA and TCG, they ran out of the black blanks, and resumed the normal aluminum blanks.

This plate is an anomaly - it's a TG- series (which should have been issued around 1967), but it has a natural 1960 tab.
The source of this plate said that the tab was original to the plate.
Either way, I wanted to include it here.
Dave Zullo

In mid-1970, the reflectorization was changed somewhere between TKE and TKH.
The surface of the plates became smoother, just like the passenger plates and other reflective types issued around 1969-1970.
It looks like these reflective plates from TK? to TNZ had clearcoat applied on top of the same reflective sheeting that was used previously from 1960 to 1970.

The tab slots went away at this point as well ... sort of. Some of the early plates used blanks with tab slots, but the slots were not punched out in the sheeting.

Thanks to Dave Zullo for the info on the reflectorization of these plates and all of the pictures !

Starting with the TOA series, reflectorization was dropped, and regular painted plates were used again.

The TQA-TQZ series was skipped because the letter Q is not used.
The TRA-TRZ and TSA-TSZ prefixes were also skipped, because the TR-A and TS-A prefixes were used on TRACTOR plates.

The TUB and TUC plates below are possible overlaps from the 1960 series.
Number TUC-502 was issued in 1960, and TUC-809 was issued in 1972 or 1973.

Dave Zullo

There were 2 different types of "W" dies used on plates in the early to mid 70's.
The most obvious differences were on these trailer samples.
The older "W" die on the left has higher center points, both on top and on the bottom.

1971 SAMPLE

1973 SAMPLE