## Using dilutions

**Adding dilutions: **
To add a dilution to a raw material, see the
raw materials section of this guide.

**Changing the dilution of a formula entry: **
When editing a formula, the dilution for each
formula entry can be selected by tapping on the formula entry.
This will open a new card, where the dilution can be changed under the 'Change dilution' heading.

The are 3 methods for changing dilution:

**Preserve weight:**This method is the default and simply changes the dilution of the formula entry.**Preserve percentage:**This method changes the dilution and sets a new weight for the formula entry to maintain the relative proportions of the materials in the formula (an additional side effect is that the total weight of the formula will vary due to the solvent added or removed and as such the absolute percentages will also change).**Exchange solvent:**This method makes use of Formulair's ability to handle solvents, and requires as a precondition that a solvent raw material (and enough of it if scaling into the solvent) exists in the formula. This method of exchange uses solvent already in the formula to 'dilute' the formula entry, meaning both the total weight and concentration of the formula can stay the same when changing dilution. This option can be powerful in scaling workflows. For example, you may wish to keep the proportions in a formula the same but scale it up. The scaled up version may then ask for a large amount of prediluted raw material which would be inconvenient to measure out in practice. Instead of having to make a large amount of this dilution in advance, you can use this exchange method to re-write you formula to use a more concentrated version of the raw material without actually changing the proportions.

## Using solvents

**Setting raw materials as solvents: **
When editing a raw material,
it can be set as a solvent by setting the 'Treat as solvent?' switch on the
raw material card. You should use this option for the substance you use to dilute your
fragrance concentrate and make any dilutions with. For alcoholic perfumery this will
be alcohol. For oil based perfumery this will be your carrier oil. For perfumery of
candles this will be your wax etc.

**Adding solvents to formulas: **
When editing a formula, simply add the solvent
like any other raw material. It will be denoted with a `droplet symbol`

in the raw
materials picker and formula entry.

## Formula scaling by formula entry

Formulair gives two options for scaling the formula with respect to a single formula entry. These can be accessed when editing a formula by tapping or clicking on the formula entry:

**Scale formula using entry weight:**Scale the formula (raw materials & solvents) such that the entry weight becomes equal to the new weight you set. See the`i`

tooltip in-app for details.**Scale formula using entry percentage:**Scale up or down the concentration of the raw materials in the formula relative to the solvent to reach the desired concentration for the selected raw material in the formula. See the`i`

tooltip in-app for details. This method allows you to increase or decrease the final concentration of the fragrance concentrate in your formula by removing or adding free solvent, i.e. that which is not already bound in dilutions. To learn how to free up solvent from dilutions, see 'Using dilutions' (above).

## Formula scaling from total

Formulair gives two options for scaling the formula with respect
to total weight, and another two options for scaling the formula with respect
to total concentration.
These can be accessed when editing a formula
by tapping or clicking on the '**Total**' entry at the bottom of the formula:

**Scale formula to total weight:**Scale the formula (raw materials & solvents) such that the total weight becomes the new total weight you set. See the`i`

tooltip in-app for details.**Scale formula by weight scaling factor:**Scale the formula (raw materials & solvents) by the scaling factor you set. See the`i`

tooltip in-app for details.**Scale formula to absolute percentage:**Scale up or down the concentration of the raw materials in the formula relative to the solvent to reach the desired concentration of raw materials in the formula. See the`i`

tooltip in-app for details. This method allows you to increase or decrease the final concentration of the fragrance concentrate in your formula by removing or adding free solvent, i.e. that which is not already bound in dilutions. To learn how to free up solvent from dilutions, see 'Using dilutions' (above).**Scale formula percentage by scaling factor:**Scale up or down the concentration of the raw materials in the formula by the given scaling factor relative to the solvent. See the`i`

tooltip in-app for details. This method allows you to increase or decrease the final concentration of the fragrance concentrate in your formula by removing or adding free solvent, i.e. that which is not already bound in dilutions. To learn how to free up solvent from dilutions, see 'Using dilutions' (above).