Questions about tatami bed size order

1. do traditionally tatamis need to be a bit smaller than the bed frame?

Tatami mats have some degree of flexibility, and could be pushed
into the bed frame even if they are 1 or 2 mm larger than it. However,
we think it would definitely be better for you to choose a tatami mat
that is about 3 mm smaller than the bed frame.

2. also, if tatamis are a bit longer then a bed frame (like 5 cm on each side) will it damage them?

We recommend the selection of a tatami size that corresponds with
the length and width of the bed frame. This will also heighten the
tatami durability.

3. what would you recommend to put on the top of tatamis for sleeping?

Ordinarily, people sleep on a futon mattress laid on tatami mats.
The igusa rush on the tatami surface is a natural material, and
humidity can therefore cause it to become mildewed. We advise our
customers to hang futon out to dry at proper intervals and to see that
rooms are well ventilated. In the case of the Tokyo Series tatami
mats, the material is resin, and there is no need to worry about the
outbreak of mildew.

190 cm × 135 cm

A room of this size requires2 tatami mats with each having the
following dimensions: 95ccm × 135ccm × 3c cm

[ Classic Black-Heri Igusa Akebono ]

● Type of tatami facing: Classic Black-Heri Igusa Akebono

https://japanese-tatamimat.com/product/mat/classic/cls-bk-ial

● Tatami size: 95 cm × 135 cm × 3 cm 2 mats

Its aroma is intense when Tatami is fresh, but it fades away over time.
The color of Tatami is green at first, but over the years it changes
into honey-color affected by sun.