Pigments that are pure enough in an “Artist” grade paint are more capable of stretching the variety of hues you desire, and will get you by with fewer tubes of paints. They are stronger and richer—so with them, a little goes a long way. They have what is called “strong tinting strength,” so that a more expensive tube of paint will highly likely last a longer time (much longer than a cheaper range of paint) because you only need to use a small dab on your palette.
Student ( Etude ) quality paints are useful for students or anyone with numerous projects and are on a tight budget. They offer a good enough range of colours and high enough quality for its price. Sennelier's Etude range are made with a higher quality than most brands in the market. I personally like to use them for underpaintings, and after the artist quality colours over them.
WHAT ARE THE DIFFERENCES?
* Widest choice of colour
* Limited colour shift over time
* Less paint coverage
* More affordable price range, especially for students with project works
* Greater colour shift than artist paints
* Good choice for large scale painting and under-painting
Paint pigments can be expensive and vary in cost. Manufacturers group colours into various price bands depending on the amount of the raw material and what the raw material is.
The binder (acrylic polymer) is relatively inexpensive in comparison. That is why artist quality paints are split into series.(e.g. Sennelier Series 1 - 6) .The higher the number, the more expensive the paint.
Student (Etude ) quality paints usually come in series 1 and 2. Or Series 3 at maximum.
You still can obtain cadmium reds or orange in student quality, and they are labeled with the word “HUE” .Eg. Cadmium Red Orange Hue 
When you see “hue” written on a paint tube it means a close ‘replica’ for a lower and affordable price of available reds and orange went into to making the colour very close to the pure cadmium pigments. So you can expect the student quality paint is never going to have the colour saturation that an artist grade paint will achieve.
Pigments vary in their transparency by nature, different paints have difference levels of opacity depending on the paint pigments chemical make up. A paint made from earth, such as an ochre ( Brown Ochre ) will be made from crushed up rock, which would be opaque and hard to see through. This will make a paint with good coverage. If you were using a paint with pigments that are man-made ( or synthetic organics), such as Quinacridone Red , it would be thinner and more translucent.
They are often labelled on a paint tube, Sennelier uses the following abbreviations:
T for transparent colours
S/T for semi-opaque colours
O opaque colours
HINT: It is very useful to understand the differences so if you need to make a highly translucent glaze, the quinacidones are excellent for glazing (thin layer of paint)
and tinting. While opaque colours cover other paints easily, and are great for underpaintings , making solid, flat areas of colour and correcting mistakes.
FUNNY BUT TRUE: If it can’t pronounced, it is usually a transparent paint, eg. quinacridone. If it comes with an ‘natural’ or 'organic' name eg ochre, umber, it will be more opaque.
3. Paint sample
On most artist quality paints there will be a colour swatch of the actual paint on the exterior of the tube. This is really helpful when deciding which paints will suit your needs.
4. Colour range
Artist grade paints have a much wider array of colours available. 36 for Etude Oil Colours and 144 for Extra -Fine Artist Quality Paints. While Sennelier's Acrylic paints come in only artist quality.
Different binders are available in different consistencies so you can have a thick paint or thin paint but the thinnest paint will have as much pigment as the thicker paint.
6. Colour shift
Some paint colours look the exact shade required when wet but changes when it dries, going slightly darker.
This is due to the binder (acrylic polymer) that is usually used.
In student quality paints a white binder generally will have been used and usually, the cheaper the paint, the greater the colour shift.
It could cause some frustration for the beginner to accurately mix the exact shade of colour required.
Using the right paints can help greatly in your progress as an artist. Don't be make the common mistake by hesitating in investing in ‘good quality’ paints, putting it off until you
become a better painter. Make your journey as an artist a truly enjoyable one.
Posted by: Desiree