Plastisol plasticisers

Functional additives for modifying plastisol properties allow you to fine-tune a mix for a particular soft bait shape and intended use. They are not interchangeable versions of the same product. Hardener and softener primarily change firmness and flexibility, Floating Additive adjusts the density of the mix, and a heat stabiliser helps slow changes in the material caused by heat exposure.

The simplest and most repeatable approach is to start with a base plastisol in a hardness grade suited to most of your planned production. A functional additive becomes useful when you want to create your own intermediate grade, adjust a smaller batch or tailor a formula to a particular mould and the required bait action. A ready-made plastisol grade is generally more practical for larger, regularly repeated batches, while a concentrated additive gives you more room for precise fine-tuning.

Plastisol hardener is used to increase the firmness and shape stability of the base mix. It makes sense for larger bodies, substantial tails, lures retrieved at higher speeds or baits used in strong current, where an overly soft material may not hold the required shape. A stiffer formula can, however, restrict the subtle movement of fine sections. Greater hardness also does not automatically mean greater tear resistance – the final performance is affected by the formulation, lure design, material thickness and rigging method.

Plastisol softener works in the opposite direction. It helps reduce firmness, increase body flexibility and make fine tails or appendages easier to activate during slow retrieves. It is especially useful for fine-tuning smaller baits, finesse profiles and formulas where you need an intermediate grade between the available base plastisol hardness levels. Excessive softening can, however, reduce shape stability, hook retention and the durability of the finished lure.

Floating Additive is designed to reduce the final density of the mix. Depending on the plastisol, dosage and lure design, it can help slow the sink rate, raise certain parts of the lure off the bottom or create a lighter, livelier body and tail action. The name Floating Additive does not guarantee that the finished lure will always float. The result is affected by the complete formulation, lure shape, pigments and other additives, as well as the final hook or weight configuration. Always test the finished lure in water in the same form in which it will actually be used.

Plastisol heat stabiliser helps slow thermal degradation within the material system for which it is intended, both during processing and when reheating leftover plastisol. It does not replace proper control of temperature and heating time, it does not arbitrarily extend the safe working range of the plastisol, and it cannot restore the original properties of material that has already been overheated. The correct working temperature is always determined by the specific base plastisol and its manufacturer’s instructions.

For the easiest and most repeatable first formula, we recommend starting with plastisol and an additive from the same brand. Combining SaBoFlex and Softbaitfishing products can be a practical alternative, but their concentrations and recommended dosages may differ. Test every new combination in a small separate batch and record the exact amount of each component. Do not automatically transfer percentages, grams or millilitres from one product to another.

Always follow the instructions for the specific additive when determining the correct dosage, order of addition and mixing method. When testing a formula, change only one variable at a time, use the same mould and compare the results only after the material has cooled completely. Monitor the temperature while heating plastisol, work in a well-ventilated area and use suitable personal protective and workshop equipment.

• Plastisol additives • Soft bait making

Frequently asked questions – plastisol plasticisers and modifiers

How do I know which plastisol modifier I need?

Choose a hardener when you need a firmer body with greater shape stability. Use a softener for a more flexible body and more responsive movement in fine sections. Floating Additive changes density and sink rate, while a heat stabiliser helps limit degradation of the mix during thermal processing.

Is liquid hardener the same as HARD plastisol?

No. HARD plastisol is a complete base plastisol with a defined hardness. Liquid hardener is a concentrated additive used to fine-tune another base plastisol and is not intended to be poured into a mould on its own.

Is softener the same as Floating Additive?

No. A softener primarily changes firmness and flexibility, while Floating Additive is specifically used to reduce the density of the mix. The STP FLOATING designation on a particular softener means that the product is intended for the floating system of that brand. It does not mean that it replaces Floating Additive or automatically creates a floating lure.

Does Floating Additive guarantee that the lure will float?

No. The additive changes the density of the mix, but the actual buoyancy is affected by the complete formulation, the shape and volume of the lure, pigments and other additives, as well as the hook, jig head or other rigging components. Both the unrigged lure and the complete rig should therefore be tested in water.

Can a heat stabiliser rescue overheated plastisol?

No. When used correctly, a heat stabiliser can slow thermal degradation, but it cannot restore the original colour or properties of material that has already been damaged. Significant darkening, smoke or an unusual smell are reasons to stop processing the material.

How much hardener, softener or other modifier should I use?

There is no universal dosage for every product. Follow the information on the specific product page or in its technical instructions and verify every new formula using a small test batch. Do not automatically convert a dosage stated in grams into the same numerical amount in millilitres.

Are all additives mixed into plastisol before heating?

There is no single procedure that applies to every product. Some hardeners and softeners are added to cold plastisol before heating, while other products may require a different procedure. Always follow the instructions provided for the specific additive.

Can I combine plastisol and an additive from different brands?

Such a combination can be a practical alternative, but without specific testing you cannot assume the same dosage or an identical result. For the simplest starting point, use plastisol and an additive from the same system. Test any cross-brand combination first in a small controlled batch.

Does harder plastisol automatically produce a more durable lure?

Not always. Greater hardness usually improves shape stability, but tear resistance is also affected by the specific formulation, material thickness, lure geometry and hook placement. A mix that is too hard can also restrict the movement of a fine tail.