The levelling thinner and mr retarder tends to produce a glossy finish especially when using an airbrush.It allows the paint to settle more, producing a smoother, hence, glossier finish.
If you need a flat finish, use Flat Base ( # 30 on the Gunze color chart ). It can be mixed directly with the paint to render it very flat. For airbrushing,mixed it with #46 ( Clear Gloss) to you get a clear flat solution that will vary in flatness depending on the ratio of both. 75 to 80 per cent Clear Gloss to 25 to 20 percent Clear Flat will produce a a good flat finish when spray over a glossy paint job. 90 percent clear gloss to 10 percent flat base will produce a semi gloss finish. Rule of thumb when mixing the two is first to mix of 50% Clear Gloss to 50% Mr Color Thinner then slowly add small amounts of flat base until you get a murky solution. Test it for your desired effect. If you want a flatter finish simply keep adding flat base in small increments until you are satisfied. Too much flat base will cause the coat you airbrushed to become whitish. When using clear gloss and clear flat, USE ONLY Mr. Color Thinner, DON'T USE the kind from the hardware store.
STC is the exclusive distributor of Gunze-Sangyo products in the Phils. so you can get most of the paints from them.
As far as I know, STC contact nos. are as follows :
Tetuan(main branch)Sta. Cruz, Manila - (02)-733-3508. Ask for Annabelle As for the others, ask for any saleperson. I'm not familiar with the other branches personnel.
Virra Mall Greenhills - (02)-721-5332
Isetann Recto Manila - (02)-733-4261
Filinvest Supermall, Alabang - (02)-850-3928
SM City North Ave. Q.C. - (02)-453-3848
There also one in SM Fairview, another in Rustan's Cubao and a new one in Alabang Town Center called Hobbitoi but I haven't got their contact nos.
I hope this helps.
Rico