I will deal with kits here produced under the brand name FROG and Tri-ang from 1955 -1976 by various divisions of Lines Bros . Ltd.1)
Strictly speaking FROG kits I remember must have been Tri-ang kits which was the brand name of FROGs produced in France to be distributed in European Community countries. But I´m not 100 % sure if original FROG kits had not been distributed concurrently in Germany. A similar situation as with Airfix and Plasty.
As far as kits with Type E boxes 2) are concerned it is very clear that these "FROGs" I remember were from Tri-ang. Best proof are the two kits depicted right which were left over unbuilt in boxes from my 60´s modelling period. Unfortunately the only items left, besides a box from the Hawk Dauntless and a box with scrap-parts.
I do not remember having boxes with 3-view drawings as boxart which looked like FROG Oxford kit depicted on the lower right with silvery colored panels at the left end.
I remember to have had the following aircraft in E boxes in constant 1:72 scale.
Airspeed Oxford II
||Miles Magister 1
|Hawker Sea Fury
I was and still are very fond of this type of boxart. Possibly the only case were I choosed a kit for the sake of boxart in my 60´s modelling phase. And FROG resp. Tri-ang released subjects of British types not made by other manufacturers in these days, which were very attractive to me. Similar to Aurora the Tri-ang kits emanated a mystic atmosphere.
I also remember to have had FROG /Tri-ang kits in small flat Type D boxes 2). I´do not know now why I bought these kits in odd, box-size scales in my phase of "serious modelling" when I should have stuck to constant 1:72 scale. Obviously I liked the types of aircraft which were modelled.
D.H. 2 Beaver
|H. P. Hampden
One hint, that they also must have been from Tri-ang comes from the color of the plastic. The Frog issues I bought lately of the Beaver and Rapide are made in a sort of a darker petrol blue . I remember that the kits I had in the 60´s had been light blue . On the other hand the FROG type D boxes look not as unfamiliar to me as is the case with type D ( 3-view ) boxes from FROG. The only example of a Tri-ang Type D box I have in my collection is the B-66 depicted on the lower right.
So were did I know the name FROG from , all the time before starting collecting in 2003 ? I assume from ads in magazines (Aermodeller, Flying Review ) .
I do not remember to have had neither early Frog or Tri-ang kits in early type C 2) boxes nor kits in later style boxes (Type F onwards) in my youth. Examples are depicted on the bottom right . I aquired them all since 2003.
Kits based on Frog moulds but manufactured by other companies :
In Lines and Hellström  words: " One of the many things making Frog kits unique is the very large number of other companies using or having used them in their own ranges. Since 1958, some fifty companies in more than a dozen countries spread over four continents have been involved. The method used ranged from purchase of Frog moulds to illegal copying of kits. Many of the other large kit companies - such as Airfix and Revell - have of course been engaged in similar transactions, but never to the same large extent."
Lines and Hellström list and describe them profusely in their book.
I consider the Frog spawn - as the authors call it - as a very interesting theme for collectors but it is surely a life´s work and costs a fortune.
Besides Tri-ang (France) which is dealt concurrently here with Frog I will review the following exponents from the Frog spawn in seperate sections , when time allows :
NOVO which I bought to be able one time to build FROG kits keeping the originals intact and
Air Lines , wich produced FROG kits in the USA from 1964- 1966 to show the new boxart from Jo Kotula.
1) I highly recommend the book Frog Aircraft 1932-1976 from Lines and Hellström  to learn more about the complicated and therefore interesting history of Lines Bros. Ltd´s flying and non flying models. For pre- 1955 FROG and Penguins please have a look at the Frog Penguin Page, too.
2) Clasification of boxes according to 
Type C box. The first style used on the second generation kits since 1955.
C 1 Had a large red/yellow/blue panel on the box top. Used for kits first released 1955-1957.
C 2 Had only a small red/yellow panel with the FROG logo in one corner of the box top. Used for new kits 1957-1962.
Type D-box. A small ,flat box which came in one size only: 19x10,5x3 cm ( 6.172x4x1 inches). The box ends and sides were always yellow . It was used for "box-size scale" kits issued new in the 1958-1959 period."
Type E box. The box top showed a three-view colour drawing of the aircaft . Introduced in 1963, it proved unsuccessful and was replaced from 1964 onwards.
For more information on package styles please have a look at reference [1 ] .
[1 ] Lines and Hellström (1989)