Ever so often I come across lamps by Itsu and Valinte at flea markets and I’m amazed that there is so little written about them. There is much information about larger companies such as Orno, Idman and Taito and it’s fairly easy to identify lamps and light fixtures by them but when it comes to the smaller companies it gets harder. This is partly due to the fact that the smaller manufacturers seldom employed well known designers but it’s also due to poor archiving and perhaps a lack of interest from historians and collectors.
I hope I do these companies some justice with the information I’ve been able to scrape together. Please use the comment field if you have something to add. Thank you.
ARIS or ARISUO
Toivo Arisuo founded Arisuo Oy in 1947 and in the following decades the company grew into a significant manufacturer of light fixtures in the municipality Kaarina near Turku. Mr. Arisuo stayed with the company as CEO until 1972. The company closed down in the end of 1982. Before that another part of the company, Aris-Tuote, was shut down in 1969.
Arisuo made lamps as well as metal and plastic articles. In the 40’s there were four people at the company including Mr. Arisuo. The company expanded in 1952 and built a factory in Kaarina. One of the its famous products in the 1950’s was a flashlight which bore the name Aris, in the 1960’s it was commercial signs in metal and in the 1970’s pressure valves. In the beginning of the 1970’s the company employed more than 200 people and it expanded with a new factory.
Arisuo did not have any well known designers on their payroll but Kai Salo worked at the company and designed lamps between 1973 and 1979. It’s believed that many models were bought from manufacturers in other countries.
VALINTE 
The light fixture manufacturer Valinte was founded in 1959 by entrepreneur Into Lintero but the name Valinte Oy seems to have been around since August 1942 in Helsinki, Malmi. The name Valinte comes from Valaisin (Lamp) and the former part of Lintero. The factory was also built in 1959 (drawn by architect Aulis Salo) and later enlarged in 1964.
The factory had their own seamstresses and made mostly lamps out of metal, sometimes combined with plastic/acrylic or opal glass. The company was renamed Lampukas Oy in the 1970’s and it was later moved to Saarijärvi where it still functions today . The factory doesn’t however make the kind of designed light fixtures it used to anymore. Lintero died in 1996.
Valinte lamps are sometimes marked V-e as in Valinte, and sometimes the name is accompanied by a serial number. There are few catalogues to come by and it seems that many lamp models were either bought from manufacturers abroad or copied from existing Finnish designs. No well known designers worked with the company during the 60’s and 70’s.
ITSU 
Itsu is short for Itä-Suomen Sähkö (eng. Eastern Finland Electricity). Kaarlo Hildén, who was CEO at Idman from 1945 to 1955, became CEO in 1961 at Itsu Oy, Itä-Suomalainen Sähkö Oy and Sähkökaluste Oy. These companies were all owned by Idman and Itsu defaulted in 1966. Idman oy was finally dissolved in 1987.
Much of Itsu’s production had resemblance to works by Paavo Tynell and Tapio Wirkkala although neither worked for Itsu at any point. It’s believed that Itsu copied or were influenced by the style of Idman’s light fixtures and since Mr. Tynell and Wirkkala worked for Idman it was an easy choice to make.
SARIO
I’ve so far found little information about Sario but the company seems to have also been called S. Sario & Kumppanit. The earliest registration of the company is from 1967 which I think might be too late to make sense.
Sario made mostly “old-fashioned” lamps and the designs seem to have been imported from other companies.
LIVAL
Lival is a family business, founded in 1945 and the company still exists. It was founded by Harald Lindström and now his son runs the company in Sipoo. The original name was Lindströmin Valaisimia (LiVal) / Lindströms Lampor and the old logo references this (Oy Lindströmin Sähkö Lindströms Elektriska Ab).
There were others as well such as Viipurin Valaisintehdas, Valaisinpaja which made lamps for Artek, Salosvalo which made lamps for Marimekko and I-valo which started making lamps in the 1970s.
Forthzine - Jonas Forth 